Kraemer, Mr. and Mrs. George (1852 - )

This biographical summary was created by the Works Progress Administration (WPA) between 1936 and 1939

Methyl salicylate as a signaling compound that contributes to forest ecosystem stability

Methyl salicylate (MeSA) is a volatile plant and microbial signaling compound involved in systemic acquired resistance (SAR) and defense against pests and microbial pathogens, and antagonists. MeSA emitted by plants is also believed to trigger SAR in neighboring plant individuals, thus contributing to the resilience of the entire plant community. In this review, we discuss volatile plant-to-plant communication processes with a special focus on MeSA and provide an overview about the occurrence of MeSA in fungi and other microbes. We summarize present findings on the role of MeSA in plants and particularly in birches (Betula spp.) and discuss the potential use of MeSA and MeSA-emitting plants in agriculture and forestry. MeSA levels in plant tissues are adjusted by methylation of salicylic acid to MeSA and the reverse process of demethylation. Some plant species possess constitutively high MeSA levels and thus are suitable for experiments of admixture of high MeSA plants, e.g., birches of the subgenera Betulenta and Acuminata in plant communities such as mixed forests. Furthermore, knowledge of candidate genes and the molecular pathways underlying high MeSA emission is expected to offer a basis for altering MeSA levels and/or the selection of high MeSA mutants.Humboldt-Universität zu Berlin (1034)Peer Reviewe

Methyl salicylate as a signaling compound that contributes to forest ecosystem stability

Methyl salicylate (MeSA) is a volatile plant and microbial signaling compound involved in systemic acquired resistance (SAR) and defense against pests and microbial pathogens, and antagonists. MeSA emitted by plants is also believed to trigger SAR in neighboring plant individuals, thus contributing to the resilience of the entire plant community. In this review, we discuss volatile plant-to-plant communication processes with a special focus on MeSA and provide an overview about the occurrence of MeSA in fungi and other microbes. We summarize present findings on the role of MeSA in plants and particularly in birches (Betula spp.) and discuss the potential use of MeSA and MeSA-emitting plants in agriculture and forestry. MeSA levels in plant tissues are adjusted by methylation of salicylic acid to MeSA and the reverse process of demethylation. Some plant species possess constitutively high MeSA levels and thus are suitable for experiments of admixture of high MeSA plants, e.g., birches of the subgenera Betulenta and Acuminata in plant communities such as mixed forests. Furthermore, knowledge of candidate genes and the molecular pathways underlying high MeSA emission is expected to offer a basis for altering MeSA levels and/or the selection of high MeSA mutants

Telekommunikationspolitik im deutschen Einigungsprozeß: Steuerung und Eigendynamik sektoraler Transformation

Exemplarisch für die Veränderung politisch-institutioneller Problemlösungsmuster analysiert der Autor die Transformationen im Telekommunikationssektor nach der Vereinigung. Trotz rascher Ausweitung der westdeutschen Telekommunikationsordnung auf den Osten erwies sich der Institutionentransfer als letzter vergeblicher Kraftakt eines Monopols gegen Privatisierung und Liberalisierung.Abbildungen Abkürzungen Vorwort Kapitel 1 Analyse sektoraler Transformationsprozesse 1.1 Telekommunikation - ein Fall geglückter Einheit 1.2 Zum analytischen Ansatz 1.3 Die Studie Kapitel 2 Das Verhältnis der deutschen Telekommunikationssektoren von 1945 bis 1989 2.1 1945 bis Mitte der sechziger Jahre: Systemteilung analog zur Teilung Deutschlands 2.1.1 Die Situation im Jahr 1945 2.1.2 Entstehung der separaten Postgebiete 2.1.3 Teilung der Telekommunikationsnetze 2.1.4 Interne technische Kopplung und räumliche Reorganisation der Netze 2.2 Mitte der sechziger Jahre bis 1974: Neuregelung der institutionellen und technischen Verhältnisse 2.2.1 Nachkriegsordnung des gegenseitigen Verhältnisses 2.2.2 Instrumentalisierung der postalischen Nachkriegsordnung für das Anerkennungsbestreben der DDR 2.2.3 Neuregelung des institutionellen und technischen Verhältnisses im Kontext der neuen Ostpolitik 2.3 1974 bis 1989: Ausbau der technischen Verbindungen geprägt von den innerdeutschen Beziehungen 2.3.1 Abkommen und Vereinbarungen 2.3.2 Verhandlungsergebnisse 2.4 Die Entwicklung des Verkehrsaufkommens im innerdeutschen Telefonverkehr von 1947 bis 1989 2.5 Telefonverkehr als Spiegel der Deutschlandpolitik Kapitel 3 Die Telekommunikationssektoren von DDR und BRD 3.1 Systemgegensatz oder deutsch-deutsche Verwandtschaft? 3.1.1 Ein Klassifikationsschema zum institutionellen Vergleich von Telekommunikationssektoren 3.1.2 Klassifikation des DDR-Telekommunikationssektors 3.1.3 Institutionen im Übergang: Die bundesdeutsche Postreform von 1989 3.1.4 Klassifikation der neuen bundesdeutschen Ordnung 3.1.5 Zur institutionellen Verwandtschaft der deutschen Telekommunkationssektoren 3.2 Akteurkonstellationen in Ost und West 3.2.1 Entscheidungsverflechtung im Telekommunikationssektor der DDR 3.2.2 DDR: Bürokratische Rivalitäten im Schatten des ZK 3.2.3 Entscheidungsverflechtung im bundesdeutschen Telekommunikationssektor 3.2.4 BRD: Zentralistische Strukturen und institutioneller Dissens 3.3 Technische Basis der sektoralen Leistungsstruktur 3.3.1 DDR: Im Teufelskreis von Ressourcenknappheit und Netzüberlast 3.3.2 BRD: Auf der Suche nach Wachstumsperspektiven 3.4 Der Status quo ante Kapitel 4 Vom Telefonstau zur Postunion - November 1989 bis März 1990 4.1 Die technischen Ausgangsprobleme: Netzüberlast 4.1.1 Verbindungen zwischen der Bundesrepublik und der DDR: Verkehrsüberlast 4.1.2 Anschlüsse am Telefonnetz der DDR: Nachfrageüberlast 4.2 Problemlösungsversuche mittels tradierter Handlungsstrategien 4.2.1 Bewältigung der Verkehrsüberlast im innerdeutschen Fernmeldeverkehr mit den Routinen der deutsch-deutschen Postverhandlungen 4.2.2 Bewältigung der Nachfrageüberlast des ostdeutschen Netzes mittels planwirtschaftlicher Handlungsstrategien 4.3 Technische Ansätze zur Problemlösung 4.3.1 Interoperabilität der Netze durch gemeinsame Standards 4.3.2 Digitalisierung der Vermittlungstechnik mit bundesdeutscher Hilfe 4.3.3 Overlaynetz und Übernahme aller westdeutschen Standards 4.4 Gesamtdeutsche Einheitlichkeit als technische Ideallösung Kapitel 5 Vorbereitung auf die Einheit - März 1990 bis Oktober 1990 5.1 Eine neue Aufgabe: Netzausbau auf Westniveau 5.2 Zentral gesteuerte Vorbereitungen auf die Vereinigung 5.2.1 Finanzierung des Ausbauprogramms 5.2.2 Organisatorische Integration der Deutschen Post 5.2.3 Planung des Netzausbaus 5.3 Übernahme des Kombinats Nachrichtenelektronik 5.3.1 Akquisitionsaktivitäten der bundesdeutschen Fernmeldeindustrie 5.3.2 Ergebnisse und Eigendynamik des Übernahmeprozesses 5.4 Beschleunigung des Ausbaus durch Liberalisierung? 5.4.1 Lizenzierung privater Mobilfunknetze für das Gebiet der DDR 5.4.2 Aufhebung des Telefondienstmonopols zugunsten privater Satellitentelefondienste 5.5 Einigung zwischen zentraler Steuerung und Eigendynamik Kapitel 6 Beschleunigung unter Druck - Oktober 1990 bis Juli 1991 6.1 Noch immer nicht erreicht: Bewältigung der Überlastprobleme 6.2 Problemlösung unter Drohung institutioneller Änderungen zu Lasten der DBP Telekom 6.2.1 Erste Bedrohung: Bewältigung der Anschlußknappheit durch Einschränkung des Netzmonopols 6.2.2 Zweite Bedrohung: Bewältigung des Ost-West-Engpasses durch Einschränkung des Telefondienstmonopols 6.2.3 Dritte Bedrohung: Einheitsbedingte finanzielle Mehrbelastung der DBP Telekom 6.3 Der letzte Kraftakt des Monopols Kapitel 7 Voraussetzungen und Determinanten sektoraler Transformation 7.1 Zur Bedeutung des Status quo ante 7.1.1 Institutionelle Verwandtschaft vereinfacht organisatorische Vereinigung 7.1.2 Gefährdete Besitzstände und Ressourcenmangel motivieren zur Kooperation 7.1.3 Technischer Rückstand erleichtert Netzmodernisierung 7.2 Determinanten des Transformationsprozesses 7.2.1 Fehlen endogener Transformationshemmnisse 7.2.2 Zentralisierte und fragmentierte sektorale Binnenstruktur 7.2.3 Situationswahrnehmung der Akteure Gesetze, Verordnungen und Verträge Literatu

(Un)expected Learning Outcomes of Virtual School Garden Exchanges in the Field of Education for Sustainable Development

Global solidarity is paramount in times of global crises and essential in Education for Sustainable Development (ESD). Virtual School Garden Exchanges (VSGEs) link local gardening with global thinking. In VSGEs, elementary and secondary school students in different parts of the world exchange information about their school gardens and related topics via digital media. Educators’ perspectives and the learning outcomes they observed in the participants of the VSGEs were the focus of this study, as there has been controversy about whether VSGEs are suitable for implementing ESD and whether VSGEs result in the learning outcomes that the educators expect them to. We conducted 20 semi-structured interviews with VSGE educators and analyzed them in an abductive and qualitative manner. The results showed substantial overlap with both the expected learning outcomes and the aims of ESD. Nevertheless, the data revealed different ways in which learners who engaged with their international peers were influenced by stereotypes and norms. On the one hand, VSGEs can lead to Othering, which is not congruent with either ESD or the expected learning outcomes. On the other hand, it can inspire Transformative Learning processes, which contribute to the aims of ESD. Therefore, depending on a complex interplay of various factors, there is potential for ESD in VSGEs, but VSGEs are not guaranteed to be a good ESD practice.Peer Reviewe

Reconfiguration, contestation, and decline: conceptualizing mature large technical systems

Large technical systems (LTS) are integral to modern lifestyles but arduous to analyze. In this paper, we advance a conceptualization of LTS using the notion of mature “phases,” drawing from insights into innovation studies, science and technology studies, political science, the sociology of infra- structure, history of technology, and governance. We begin by defining LTS as a unit of analysis and explaining its conceptual utility and novelty, situating it among other prominent sociotechnical theories. Next, we argue that after LTS have moved through the (overlapping) phases proposed by Thomas Hughes of invention, expansion, growth, momentum, and style,mature LTS undergo the additional (overlapping) phases of reconfiguration, contestation (subject to pressures such as drift and crisis), and eventually stagnation and decline. We illustrate these analytical phases with historical case studies and the conceptual literature, and close by suggesting future research to refine and develop the LTS framework, particularly related to more refined typologies, temporal dimensions, and a broadening of system users. We aim to contribute to theoretical debates about the coevolution of LTS as well as empirical discussions about system-related use, socio- technical change, and policy-making

Soil degradation and herbicide pollution by repeated cassava monoculture within Thailand’s conservation region

In a national park in Northeast Thailand, agricultural land has been converted from natural forest by small-scale farmers for cassava agriculture. We hypothesise that long-termed cassava monoculture leads to the degradation of soil properties. To test the hypothesis, we conducted a five-year (2016–2020) study on the physical and chemical properties of soil in cassava farmland, and also examined the soil properties of its adjacent natural forests, as a control. The examined cassava farmland was converted from the natural forest during the five years from 2011 to 2015. The significant decrease in organic carbon and the increases in exchangeable potassium and bulk density were found in 2016, indicating that these soil properties varied quickly following the farmland conversion. On the other hand, the significant increase in soil nitrogen and the decrease in pH were found later in 2020, indicating that these soil properties were gradually altered by repeated agricultural activities, such as fertilizer application and trampling. In contrast, there were no significant differences in available phosphate, electrical conductivity, cation exchange capacity, and the soil texture (the fractions of sand, silt, and clay) among the forest and farmland soils. The cation exchange capacity was positively correlated to the fraction of clay, the organic carbon, and pH. The use of glyphosate and paraquat herbicides is prohibited within national parks in Thailand. However, in 2020, glyphosate was detected in farmland soil (up to 5.0 mg kg⁻¹) during both the rainy and dry seasons, and glyphosate (up to 2.5 mg l⁻¹) was detected in stream water from the farmland during the dry season at least in 2020. Soil degradation and herbicide pollution may carry a high risk of causing irreversible changes in terrestrial ecosystems. We discuss the root causes of this issue from perspectives of agricultural production, economy, and the environmental impact, and propose effective policy measures

Plant vascular development--connective tissue connecting scientists: updates and trends at the PVB 2013 conference.

In July 2013, the scientific community fascinated by plant vascular biology (PVB) was cordially welcomed to Helsinki, the capital of Finland, to discuss the latest advances in the field. This meeting was the Third International Conference on PVB, following the successful meetings organized in Taiwan and the United States. Approximately 200 scientists from all around the world participated in PVB2013, which was characterized by lively scientific discussions in a relaxed atmosphere. The meeting was rich in topics and disciplines covering vascular biology from the early embryo to the mature plant, from the root tip to aerial organs, all linked by an appreciation of the crucial connective role of vascular tissues in plant growth and development. In this report, we briefly summarize some of the contributions presented during PVB2013 focusing on the development of vascular tissues (Figs 1 and 2). This special issue also collects a number of exciting papers with a central theme of plant vascular development

First steps in studying the origins of secondary woodiness in Begonia (Begoniaceae): Combining anatomy, phylogenetics, and stem transcriptomics

Since Darwin’s observation that secondary woodiness is common on islands, the evolution of woody plants fromherbaceous ancestors has been documented in numerous angiosperm groups. However, the evolutionary processesthat give rise to this phenomenon are poorly understood. To begin addressing this we have used a range ofapproaches to study the anatomical and genetic changes associated with the evolution and development ofsecondary woodiness in a tractable group. Begonia is a large, mainly herbaceous, pantropical genus that showsmultiple shifts towards secondarily woody species inhabiting mainly tropical montane areas throughout the world.Molecular phylogenies, including only a sample of the woody species in Begonia, indicated at least eight instancesof a herbaceous–woody transition within the genus. Wood anatomical observations of the five woody speciesstudied revealed protracted juvenilism that further support the secondary derived origin of wood within Begonia.To identify potential genes involved in shifts towards secondary woodiness, stem transcriptomes of wooddevelopment in B. burbidgei were analysed and compared with available transcriptome datasets for the non-woodyB. venustra, B. conchifolia, and Arabidopsis, and with transcriptome datasets for wood development in Populus.Results identified a number of potential regulatory genes as well as variation in expression of key biosyntheticenzymes. </div