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Synechocystis sp. PCC 6803 Requires the Bidirectional Hydrogenase to Metabolize Glucose and Arginine Under Oxic Conditions
(2022-05-31)
The cyanobacterium Synechocystis sp.PCC 6803 possesses a bidirectional NiFe-hydrogenase, HoxEFUYH. It functions to produce hydrogen under dark, fermentative conditions and photoproduces hydrogen when dark-adapted cells are illuminated. Unexpectedly, we found that the deletion of the large subunit of the hydrogenase (HoxH) in Synechocystis leads to an inability to grow on arginine and glucose under continuous light in the presence of oxygen. This is surprising, as the hydrogenase is an oxygen-sensitive enzyme. In ...
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Food Flows and the Roles of Cities in West African Food Distribution Networks
(2022-05-31)
In West Africa, rampant urbanization is changing food systems, including the magnitude and composition of food flows and the length of supply chains. An increasing body of literature discusses pathways to sustainable transformation of urban food systems taking into account links between urban and rural spaces. Research and policy have focused on the role of cities as consumption centers receiving food from local, regional, and global hinterlands. This study aims at widening the perspective on the role of cities in ...
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Energy and Exergy Based Thermal Analysis of a Solar Assisted Yogurt Processing Unit
(2022-06-01)
Energy and exergy based thermal analysis was conducted for a solar assisted yogurt processing unit capable of performing required heating and cooling processes in a single container. The system consisted of a round-shaped fermentation chamber connected with a hot water storage tank coupled with an evacuated tube collector and a pillow plate at the bottom of the chamber for cooling through a PV-operated refrigeration unit. Experiments were conducted using three different volumes of cow’s raw milk (30, 40, and 50 L). ...
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Der Algorithmus, meine Arbeit und Ich – Einfluss von Algorithmen auf Content Creator:innen der Video Plattform YouTube
(2022-01-24)
Dieser Beitrag in der Zeitschrift „Gruppe. Interaktion. Organisation. (GIO)“ nimmt auf den Einfluss von Algorithmen der Video-Plattform YouTube auf den Arbeitsalltag von Content-Creator:innen Bezug. Für den Aufbau eines erfolgreichen, also Abonnent:innen-starken Kanals und einer beruflichen Tätigkeit als Content-Creator:in, müssen YouTuber:innen sich der Wirkweisen der eingesetzten Algorithmen bewusst sein. Es wird dargestellt, welchen Einfluss Spracherkennungs- und Analysealgorithmen auf die Sprache und das Verhalten ...
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Mapping the field of research on African higher education: a review of 6483 publications from 1980 to 2019
(2020-11-16)
Following a global trend, higher education (HE) in Africa has also become a complex enterprise, potentially demanding specific expertise in higher education research. However, despite this, there is a dearth of analysis into the state of research on African HE. This paper seeks to fill this gap by mapping and analysing African HE research. We undertake a systematic review of 6483 articles and books focusing on African HE published from 1980 to 2019 in indexed and non-indexed journals and book-publishers. We particularly ...
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Strategic framing of genome editing in agriculture: an analysis of the debate in Germany in the run-up to the European Court of Justice ruling
(2021-10-09)
New techniques in genome editing have led to a controversial debate about the opportunities and uncertainties they present for agricultural food production and consumption. In July 2018, the Court of Justice of the European Union defined genome editing as a new process of mutagenesis, which implies that the resulting organisms count as genetically modified and are subject, in principle, to the obligations of EU Directive 2001/18/EG. This paper examines how key protagonists from academia, politics, and the economy ...
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Das Potenzial kooperativen Lernens ausschöpfen: Die Bedeutung der transaktiven Kommunikation für eine lernwirksame Zusammenarbeit
(2021-10-26)
Kooperatives Lernen eröffnet Chancen und birgt gleichzeitig Risiken für den Wissenserwerb. Der Beitrag arbeitet die Bedeutung der transaktiven Kommunikation als zentralen Wirkmechanismus für den genuinen Mehrwert kooperativen Lernens heraus. Unter transaktiver Kommunikation wird die fachinhaltliche Bezugnahme auf den Lernpartner verstanden, wobei niedrig-transaktive (z.B. paraphrasierende) von hoch-transaktiven (z.B. integrierenden) Äußerungen unterschieden werden. Es werden Bedingungen, unter denen sich transaktive ...
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The financialization of remittances and the individualization of development: A new power geometry of global development
(2021-08-23)
The article argues that the increasing financialization of remittances produces an enormous shift in the political economy of development and contributes to a new power geometry of development. Exploring this power geometry, the article focuses on three main issues: First, migrants intend to support their friends and families on an individual level as remittance senders, and together with the corresponding recipients they form a translocal moral economy. On a macro level, the value of these transactions is high when ...
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High optical gain in InP-based quantum-dot material monolithically grown on silicon emitting at telecom wavelengths
(2022-04-01)
We describe the fabrication process and properties of an InP based quantum dot (QD) laser structure grown on a 5° off-cut silicon substrate. Several layers of QD-based dislocation filters embedded in GaAs and InP were used to minimize the defect density in the QD active region which comprised eight emitting dot layers. The structure was analyzed using high resolution transmission electron microscopy, atomic force microscopy and photoluminescence. The epitaxial stack was used to fabricate optical amplifiers which ...
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Adsorption of PCE in alkali-activated materials analysed by fluorescence microscopy
(2021-10-18)
The realisation of high-performance concrete mixtures requires the use of superplasticizers to achieve a low water/binder ratio and thus high strengths. Polycarboxylate ethers (PCE) are mostly used as superplasticizers. The effectiveness of these superplasticizers depends on their chemical structure, the binders’ alkaline environment and the ions present in the pore solution of the binder. In high alkaline systems like some alkali-activated materials no effective superplasticizer have been found yet. To unravel the ...