„Selbstzeugnis einer vergangenen Gegenwart“. Wiederverwertung historischer Filmdokumente

Has the history of film digitization ever been incorporated in questions of evidence and knowledge production? The digitization of thousands of films from the former Institute for Scientific Film (IWF) that is currently underway gives an occasion to think about the provenance and reuses of filmic images as well as the ways in which they claim to produce scientific (or in this case, historical) evidence. In the years between 1956 and 1960, the German Social Democrat, historian and filmmaker Friedrich “Fritz” Terveen initiated a film series that used historical found film footage in order to educate university students about contemporary history. The first small series of films was entitled Airship Aviation in Germany which consisted of four short films using found footage of zeppelin flights, of which the earliest images stem from around 1904 and the latest from 1937, the moment of the “Hindenburg disaster.” This article explores how Terveen sought to shape the political landscape of history teaching in the new Federal Republic of Germany by first setting up nation-wide visual archives to host historical film documents, and secondly by seeking to improve the political education of a new generation of young Germans with the aid of the moving image.Wurde die Geschichte der Filmdigitalisierung jemals in Fragen der Beweis- und Wissensproduktion einbezogen? Die gerade stattfindende Digitalisierung von vielen Tausend Filmen des ehemaligen Instituts für den Wissenschaftlichen Film (IWF) gibt Anlass, über die Provenienz und Wiederverwendung von Filmbildern nachzudenken als auch über die Art und Weise, in der sie behaupten, wissenschaftliche (oder in diesem Fall historische) Evidenz zu produzieren. In den Jahren von 1956 bis etwa 1960 initiierte der deutsche Sozialdemokrat, Historiker und Filmemacher Friedrich „Fritz“ Terveen Filmreihen, die mit vorgefundenem Filmmaterial Hochschulstudent*innen über Zeitgeschichte aufklären sollten. Die erste kleine Filmreihe darunter war Luftschifffahrt in Deutschland, die vier kleine Filme mit gefundenem Filmmaterial über Zeppelinflüge umfasste, von denen die frühesten Bilder aus der Zeit um 1904 und die letzten aus dem Jahr 1937 stammen und die „Hindenburg-Katastrophe“ zeigen. In diesem Artikel soll gezeigt werden, wie Terveen die politische Landschaft des Geschichtsunterrichts in der neu gegründeten Bundesrepublik Deutschland zu gestalten suchte, indem er erstens danach strebte, ein bundesweites Bildarchiv mit historischen Filmdokumenten einzurichten und zweitens die politische Bildung einer neuen Generation junger Deutscher mithilfe des bewegten Bildes verbessern wollte.Humboldt-Universität zu Berlin (1034)Peer Reviewe

Soil biochemistry and microbial activity in vineyards under conventional and organic management at Northeast Brazil.

The São Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that orgThe São Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that organic fertilization can improve soil quality, we compared the effects of conventional and organic soil management on microbial activity and mycorrhization of seedless grape crops. We measured glomerospores number, most probable number (MPN) of propagules, richness of arbuscular mycorrhizal fungi (AMF) species, AMF root colonization, EE-BRSP production, carbon microbial biomass (C-MB), microbial respiration, fluorescein diacetate hydrolytic activity (FDA) and metabolic coefficient (qCO2). The organic management led to an increase in all variables with the exception of EE-BRSP and qCO2. Mycorrhizal colonization increased from 4.7% in conventional crops to 15.9% in organic crops. Spore number ranged from 4.1 to 12.4 per 50 g-1 soil in both management systems. The most probable number of AMF propagules increased from 79 cm-3 soil in the conventional system to 110 cm-3 soil in the organic system. Microbial carbon, CO2 emission, and FDA activity were increased by 100 to 200% in the organic crop. Thirteen species of AMF were identified, the majority in the organic cultivation system. Acaulospora excavata, Entrophospora infrequens, Glomus sp.3 and Scutellospora sp. were found only in the organically managed crop. S. gregaria was found only in the conventional crop. Organically managed vineyards increased mycorrhization and general soil microbial activity

Early changes in apoplast composition associated with defence and disease in interactions between Phaseolus vulgaris and the halo blight pathogen Pseudomonas syringae pv. phaseolicola

The apoplast is the arena in which endophytic pathogens such as Pseudomonas syringae grow and interact with plant cells. Using metabolomic and ion analysis techniques, this study shows how the composition of Phaseolus vulgaris leaf apoplastic fluid changes during the first six hours of compatible and incompatible interactions with two strains of Pseudomonas syringae pv. phaseolicola (Pph) that differ in the presence of the genomic island PPHGI-1. Leaf inoculation with the avirulent island-carrying strain Pph 1302A elicited effector-triggered immunity (ETI) and resulted in specific changes in apoplast composition, including increases in conductivity, pH, citrate, γ-aminobutyrate (GABA) and K+, that are linked to the onset of plant defence responses. Other apoplastic changes, including increases in Ca2+, Fe2/3+ Mg2+, sucrose, β-cyanoalanine and several amino acids, occurred to a relatively similar extent in interactions with both Pph 1302A and the virulent, island-less strain Pph RJ3. Metabolic footprinting experiments established that Pph preferentially metabolizes malate, glucose and glutamate, but excludes certain other abundant apoplastic metabolites, including citrate and GABA, until preferred metabolites are depleted. These results demonstrate that Pph is well-adapted to the leaf apoplast metabolic environment and that loss of PPHGI-1 enables Pph to avoid changes in apoplast composition linked to plant defences

Characterization and intracellular localization of putative Chlamydia pneumoniae effector proteins

We here describe four proteins of Chlamydia pneumoniae, which might play a role in host-pathogen interaction. The hypothetical bacterial proteins CPn0708 and CPn0712 were detected in Chlamydia pneumoniae-infected host cells by indirect immunofluorescence tests with polyclonal antisera raised against the respective proteins. While CPn0708 was localized within the inclusion body, CPn0712 was identified in the inclusion membrane and in the surrounding host cell cytosol. CPn0712 colocalizes with actin, indicating its possible interaction with components of the cytoskeleton. Investigations on CPn0809 and CPn1020, two Chlamydia pneumoniae proteins previously described to be secreted into the host cell cytosol, revealed colocalization with calnexin, a marker for the ER. Neither CPn0712, CPn0809 nor CPn1020 were able to inhibit host cell apoptosis. Furthermore, transient expression of CPn0712, CPn0809 and CPn1020 by the host cell itself had no effect on subsequent infection with Chlamydia pneumoniae. However, microarray analysis of CPn0712-expressing host cells revealed six host cell genes which were regulated as in host cells infected with Chlamydia pneumoniae, indicating the principal usefulness of heterologous expression to study the effect of Chlamydia pneumoniae proteins on host cell modulation

The Arabidopsis cytochrome P450 CYP86A1 encodes a fatty acid ω-hydroxylase involved in suberin monomer biosynthesis

The lipophilic biopolyester suberin forms important boundaries to protect the plant from its surrounding environment or to separate different tissues within the plant. In roots, suberin can be found in the cell walls of the endodermis and the hypodermis or periderm. Apoplastic barriers composed of suberin accomplish the challenge to restrict water and nutrient loss and prevent the invasion of pathogens. Despite the physiological importance of suberin and the knowledge of the suberin composition of many plants, very little is known about its biosynthesis and the genes involved. Here, a detailed analysis of the Arabidopsis aliphatic suberin in roots at different developmental stages is presented. This study demonstrates some variability in suberin amount and composition along the root axis and indicates the importance of ω-hydroxylation for suberin biosynthesis. Using reverse genetics, the cytochrome P450 fatty acid ω-hydroxylase CYP86A1 (At5g58860) has been identified as a key enzyme for aliphatic root suberin biosynthesis in Arabidopsis. The corresponding horst mutants show a substantial reduction in ω-hydroxyacids with a chain length <C20, demonstrating that CYP86A1 functions as a hydroxylase of root suberized tissue. Detailed expression studies revealed a strong root specificity and a localized expression in the root endodermis. Transgenic expression of CYP86A1 fused to GFP distributed CYP86A1 to the endoplasmic reticulum, indicating that suberin monomer biosynthesis takes place in this sub-cellular compartment before intermediates are exported in the apoplast

Patterns of Plant Biomass Partitioning Depend on Nitrogen Source

Nitrogen (N) availability is a strong determinant of plant biomass partitioning, but the role of different N sources in this process is unknown. Plants inhabiting low productivity ecosystems typically partition a large share of total biomass to belowground structures. In these systems, organic N may often dominate plant available N. With increasing productivity, plant biomass partitioning shifts to aboveground structures, along with a shift in available N to inorganic forms of N. We tested the hypothesis that the form of N taken up by plants is an important determinant of plant biomass partitioning by cultivating Arabidopsis thaliana on different N source mixtures. Plants grown on different N mixtures were similar in size, but those supplied with organic N displayed a significantly greater root fraction. 15N labelling suggested that, in this case, a larger share of absorbed organic N was retained in roots and split-root experiments suggested this may depend on a direct incorporation of absorbed amino acid N into roots. These results suggest the form of N acquired affects plant biomass partitioning and adds new information on the interaction between N and biomass partitioning in plants

Plastidial Starch Phosphorylase in Sweet Potato Roots Is Proteolytically Modified by Protein-Protein Interaction with the 20S Proteasome

Post-translational regulation plays an important role in cellular metabolism. Earlier studies showed that the activity of plastidial starch phosphorylase (Pho1) may be regulated by proteolytic modification. During the purification of Pho1 from sweet potato roots, we observed an unknown high molecular weight complex (HX) showing Pho1 activity. The two-dimensional gel electrophoresis, mass spectrometry, and reverse immunoprecipitation analyses showed that HX is composed of Pho1 and the 20S proteasome. Incubating sweet potato roots at 45°C triggers a stepwise degradation of Pho1; however, the degradation process can be partially inhibited by specific proteasome inhibitor MG132. The proteolytically modified Pho1 displays a lower binding affinity toward glucose 1-phosphate and a reduced starch-synthesizing activity. This study suggests that the 20S proteasome interacts with Pho1 and is involved in the regulation of the catalytic activity of Pho1 in sweet potato roots under heat stress conditions

A mutation in GDP-mannose pyrophosphorylase causes conditional hypersensitivity to ammonium, resulting in Arabidopsis root growth inhibition, altered ammonium metabolism, and hormone homeostasis

Ascorbic acid (AA) is an antioxidant fulfilling a multitude of cellular functions. Given its pivotal role in maintaining the rate of cell growth and division in the quiescent centre of the root, it was hypothesized that the AA-deficient Arabidopsis thaliana mutants vtc1-1, vtc2-1, vtc3-1, and vtc4-1 have altered root growth. To test this hypothesis, root development was studied in the wild type and vtc mutants grown on Murashige and Skoog medium. It was discovered, however, that only the vtc1-1 mutant has strongly retarded root growth, while the other vtc mutants exhibit a wild-type root phenotype. It is demonstrated that the short-root phenotype in vtc1-1 is independent of AA deficiency and oxidative stress. Instead, vtc1-1 is conditionally hypersensitive to ammonium (NH4+). To provide new insights into the mechanism of NH4+ sensitivity in vtc1-1, root development, NH4+ content, glutamine synthetase (GS) activity, glutamate dehydrogenase activity, and glutamine content were assessed in wild-type and vtc1-1 mutant plants grown in the presence and absence of high NH4+ and the GS inhibitor MSO. Since VTC1 encodes a GDP-mannose pyrophosphorylase, an enzyme generating GDP-mannose for AA biosynthesis and protein N-glycosylation, it was also tested whether protein N-glycosylation is affected in vtc1-1. Furthermore, since root development requires the action of a variety of hormones, it was investigated whether hormone homeostasis is linked to NH4+ sensitivity in vtc1-1. Our data suggest that NH4+ hypersensitivity in vtc1-1 is caused by disturbed N-glycosylation and that it is associated with auxin and ethylene homeostasis and/or nitric oxide signalling

Phosphorous Efficiency and Tolerance Traits for Selection of Sorghum for Performance in Phosphorous-Limited Environments

Sorghum (Sorghum bicolor (L.) Moench) is widely cultivated in West Africa (WA) on soils with low phosphorus (P) availability. Large genetic variation for grain yield (GY) under low-P conditions was observed among WA sorghum genotypes, but information is lacking on the usefulness of P-tolerance ratios (relative performance in –P [no P fertilizer] vs. +P [with P fertilizer] conditions) and measures of P-acquisition and internal P-use efficiency as selection criteria for enhancing GY under low-P conditions. We evaluated 70 WA sorghum genotypes for GY performance under −P and +P conditions for 5 yr in two locations in Mali and assessed P acquisition (e.g., P content in biomass) and P-use efficiency (e.g., grain produced per unit P uptake) traits under −P and +P conditions in one site in 2010. Significant genetic variation existed for all P-tolerance ratios across multiple sites. Photoperiod-sensitive landrace genotypes showed significantly better P tolerance and less delay of heading under P-limited conditions compared with photoperiod-insensitive varieties. Genotypic correlations of P-tolerance ratios to GY under −P were moderate. Phosphorous acquisition and P-use efficiency traits independent of harvest index were of similar importance for GY under −P conditions in statistically independent trials. However grain-P and stover-P concentrations from one −P trial showed only weak correlations with GYs in statistically independent trials. Highest predicted gains for −P GY were obtained by theoretical index selection based on −P GY combined with P-use efficiency traits (e.g., low-grain P concentration). Such index selection is expected to achieve both increased sorghum productivity and P sustainability in the P-limited WA production systems