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The chloroplast RNA–binding protein CP29A supports rbcL expression during cold acclimation
No full textThe chloroplast genome encodes key components of the photosynthetic light reaction machinery as well as the large subunit of the enzyme central for carbon fixation, Ribulose-1,5-bisphosphat-carboxylase/-oxygenase (RuBisCo). Its expression is predominantly regulated posttranscriptionally, with nuclear-encoded RNA-binding proteins (RBPs) playing a key role. Mutants of chloroplast gene expression factors often exhibit impaired chloroplast biogenesis, especially in cold conditions. Low temperatures pose a challenge for plants as this leads to electron imbalances and oxidative damage. A well-known response of plants to this problem is to increase the production of RuBisCo and other Calvin Cycle enzymes in the cold, but how this is achieved is unclear. The chloroplast RBP CP29A has been shown to be essential for cold resistance in growing leaf tissue of Arabidopsis thaliana. Here, we examined CP29A–RNA interaction sites at nucleotide resolution. We found that CP29A preferentially binds to the 5′-untranslated region of rbcL, downstream of the binding site of the pentatricopeptide repeat protein MATURATION OF RBCL 1 (MRL1). MRL1 is an RBP known to be necessary for the accumulation of rbcL. In Arabidopsis mutants lacking CP29A, we were unable to observe significant effects on rbcL, possibly due to CP29A’s restricted role in a limited number of cells at the base of leaves. In contrast, CRISPR/Cas9-induced mutants of tobacco NtCP29A exhibit cold-dependent photosynthetic deficiencies throughout the entire leaf blade. This is associated with a parallel reduction in rbcL mRNA and RbcL protein accumulation. Our work indicates that a chloroplast RNA–binding protein contributes to cold acclimation of RbcL production.Significance: This study unveils the role of CP29A, a chloroplast-localized RNA–binding protein, in facilitating plants’ acclimation to cold environments. We found that a preferred target of CP29A is the rbcL messenger RNA, encoding a subunit of RuBisCO—a key enzyme in photosynthesis and the most abundant protein on Earth. Our study reveals that CP29A is essential for the full accumulation of rbcL mRNA and for the accumulation of the rbcL-encoded large subunit of Ribulose-1, 5-bisphosphat-carboxylase/-oxygenase in response to cold exposure, functioning through its binding to the 5′-untranslated regions (UTRs) of rbcL.Peer Reviewe
Cueing distractors is effective when the incentive to suppress is high
No full textAvoiding distraction is critical for our ability to focus, and recent years have seen an increased interest in attentional suppression mechanisms. We now know that we implicitly learn about statistical regularities of our environment, which facilitates inhibition, but it remains unclear if distractors can also be suppressed voluntarily when advance information about their occurrence becomes available. Reasoning that such top-down suppression is likely an effortful process requiring a certain degree of motivation, we aimed to show that distractor cueing can effectively reduce distraction when the incentive is high. In an additional singleton search task, we maximized the incentive to suppress by presenting cues that validly indicated the distractor’s specific location and colour, and by rewarding successful suppression. For correct responses, participants received either a low or high reward, depending on distractor colour. Responses were faster in trials with predictive cues than in trials with cues that did not provide any information. These cueing benefits increased over the course of the experiment. Reward magnitude also affected reaction times, indicating that high-reward singletons were more distracting, but did not interact with cueing condition. This performance pattern was complemented by modulations of the PD, a lateralized event-related potential component reflecting active suppression: Smaller amplitudes, indicating that less suppression was required, were observed for low- versus high-reward distractors and, more importantly, for distractors following predictive versus nonpredictive cues. These findings provide proof-of-principle that salient distractors can be anticipatorily suppressed in a top-down manner and highlight the importance of motivation for this voluntary operation.Open Access funding enabled and organized by Projekt DEAL.Deutsche Forschungsgemeinschafthttp://dx.doi.org/10.13039/501100001659Humboldt-Universität zu Berlin (1034)Peer Reviewe
The Political Ecology of Forests in Assam
No full textDie nordöstliche Region Indiens (NER) bildet Grenzgebiete, die als Schauplatz für Auseinandersetzungen um Identitäten, Land und Naturpolitik dienen. Die Bundesstaaten blicken auf eine Geschichte ethnisch umstrittener Grenzen und in jüngster Zeit auf gewollte Beziehungen zum Rest Indiens zurück. Die Arbeit präsentiert einen ethnografischen Bericht über Feldforschungen in Assam und zielt darauf ab, die Komplexität des historischen Verständnisses von Natur, Land und Wäldern zu ergründen. Sie untersucht die komplexe Beziehung zwischen Natur und Territorium in Grenzgebieten und untersucht historische Übergänge von der britischen Kolonialherrschaft zu bewaffneten Aufständen nach der Unabhängigkeit sowie die gegenwärtigen Auswirkungen des neoliberalen Entwicklungs- und Naturschutzes. Mit Fokus auf Assam, insbesondere auf die Mising- und Bodo-Gemeinden, untersucht die Studie die umstrittenen Waldlandschaften und behandelt Fragen der Identitätssicherung, Landnutzung und des Landbesitzes. Die Studie befasst sich mit Gemeindegeschichten, Herausforderungen im Lebensunterhalt und Dilemmata der Waldabhängigkeit, die von verschiedenen Stimmen geäußert werden, und bietet ein differenziertes Verständnis der Konzeptualisierung und Funktionsweise von Wäldern in der Region.The North-Eastern region of India (NER) constitutes borderlands that serve as a field for the contestation of identities, land and the politics surrounding nature. The states have a history of ethnically contested borders and recently contrived relations with the rest of India. The thesis presents an ethnographic account of fieldwork conducted in Assam, aiming to elaborate on the complexities inherent in the historical understanding of nature, land, and forests. The thesis explores the intricate relationship between nature and territory in borderlands, examining historical transitions from British colonial frameworks to post-independence armed rebellions, and contemporary impacts of neoliberal developmentalism and conservation. Focusing on Assam, particularly the Mising and Bodo communities, the study delves into the contested landscapes of forests, addressing issues of identity assertion, land utilization, and ownership. The study engages community histories, livelihood challenges, and forest dependence dilemmas expressed by diverse voices, providing a nuanced understanding of the conceptualization and functioning of forests in the regio
Ramsey-Bordé atom interferometry with a thermal strontium beam for a compact optical clock
No full textThe article processing charge was funded by the Open Access Publication Fund of Humboldt-Universität zu Berlin.Compact optical atomic clocks have become increasingly important in field applications and clock networks. Systems based on Ramsey-Bordé interferometry (RBI) with a thermal atomic beam seem promising to fill a technology gap in optical atomic clocks, as they offer higher stability than optical vapour cell clocks while being less complex than cold atomic clocks.Peer Reviewe
Elfte Änderung der fachspezifischen Studien- und Prüfungsordnung für den Masterstudiengang Economics and Management Science (MEMS) (AMB Nr. 60/2016)
No full textPolicy process theory development: Perspectives from European junior scholars
No full textThe development of policy process theories is progressing rapidly. Scholars increasingly apply these theories originated in the US to different contexts and continents, such as Europe. Furthermore, scholars at different career stages, including junior scholars, work on and with these theories. Focusing on junior scholars, this paper poses the following question: What are the key considerations of European junior scholars engaging in policy process theory development? We present three observations: The first observation refers to the general construction of a research project contributing to theory development. The second observation investigates how teaching policy process research and public policy, in general, can advance theory development. The third observation focuses on how to bridge the science‐practice gap as a junior scholar working on policy process theories. The three observations highlight the potential of making use of your own agency as a junior scholar engaging in policy process theory development in Europe.政策过程理论正得到快速发展。学者越来越多地将这些起源于美国的理论应用于不同的情境和大洲, 例如欧洲。此外, 不同职业阶段的学者 (包括青年学者) 都在研究和运用这些理论。本文以青年学者为重点, 提出了以下问题:欧洲青年学者参与政策过程理论发展的主要考虑因素是什么？我们提出了三点观察:第一点观察指的是有助于理论发展的研究项目的总体构建。第二点观察调查了“教授政策过程研究和公共政策”一事如何促进理论发展。第三点观察聚焦于作为一名从事政策过程理论研究的青年学者如何填补科学与实践的差距。这三点观察强调了作为一名在参与欧洲政策过程理论发展的青年学者在利用自身能力方面的潜力。El desarrollo de teorías sobre procesos de políticas está progresando rápidamente. Los académicos aplican cada vez más estas teorías originadas en los Estados Unidos a diferentes contextos y continentes, como Europa. Además, académicos en diferentes etapas de su carrera, incluidos académicos jóvenes, trabajan en y con estas teorías. Centrándose en los académicos jóvenes, este artículo plantea la siguiente pregunta: ¿Cuáles son las consideraciones clave de los académicos jóvenes europeos que participan en el desarrollo de teorías sobre procesos de políticas? Presentamos tres observaciones: la primera observación se refiere a la construcción general de un proyecto de investigación que contribuya al desarrollo de la teoría. La segunda observación investiga cómo la enseñanza de la investigación sobre procesos de políticas y las políticas públicas en general pueden hacer avanzar el desarrollo de la teoría. La tercera observación se centra en cómo cerrar la brecha entre la ciencia y la práctica como académico joven que trabaja en teorías sobre procesos de políticas. Las tres observaciones destacan el potencial de hacer uso de su propia agencia como académico joven que participa en el desarrollo de teorías sobre procesos de políticas en Europa.German Federal Ministry of Research and EducationPeer Reviewe
Appendices to: On Greenberg’s Classification of African Languages
No full textDie Klassifikation der Sprachen Afrikas durch Greenberg – typischerweise verstanden als seine Einteilung von 1963 in vier Familien – war enorm einflussreich. Obwohl frühere Arbeiten bereits auf verschiedene Mängel hingewiesen haben, untersuchen wir in diesem Papier systematisch die Vollständigkeit, Genauigkeit (im Vergleich zum aktuellen Wissensstand) und die Beweisgrundlage der Greenbergschen Klassifikation von 1963. Dieser Vergleich zeigt, dass die Qualität dieser Klassifikation viel mit den allgemein abgelehnten Klassifikationen von Greenberg für Sprachen in anderen Teilen der Welt gemeinsam hat. Darüber hinaus konnte sie nicht durch eine strikte Anwendung der angeblichen Methode des „Massensvergleichs“ entstanden sein. Eine bessere Erklärung für das Ergebnis der Klassifikation ist vielmehr ein Verfahren, bei dem ein Forscher dazu verleitet wird, zufällige Ähnlichkeiten als Beweis für genealogische Beziehungen zu interpretieren. Es ist schwierig zu bestimmen, warum Greenbergs Klassifikation der afrikanischen Sprachen so einflussreich wurde, aber wir geben dennoch einige wichtige Hinweise.Greenberg's classification of the languages of Africa --- typically understood as his 1963 division into 4 families --- has been enormously influential. Although earlier work has pointed out various shortcomings, in the present paper we systematically examine the completeness, accuracy (against the current state-of-the-art) and evidential basis of the Greenberg 1963 classification. This comparison shows that the quality of this classification has much in common with the commonly rejected classifications by Greenberg of languages in the rest of the world. Moreover, it could not possibly have been produced by a strict application of the alleged method of 'mass comparison'. A better explanation for the classification outcome is rather a procedure wherein a researcher is lead to interpret chance resemblances as evidence of genealogical relationship. It is difficult to pinpoint why Greenberg's classification of African languages became so influential, but we nevertheless provide a few key pointers