A Small Chloroplast-Encoded Protein as a Novel Architectural Component of the Light-Harvesting Antenna

A small conserved open reading frame in the plastid genome, ycf9, encodes a putative membrane protein of 62 amino acids. To determine the function of this reading frame we have constructed a knockout allele for targeted disruption of ycf9. This allele was introduced into the tobacco plastid genome by biolistic transformation to replace the wild-type ycf9 allele. Homoplasmic ycf9 knockout plants displayed no phenotype under normal growth conditions. However, under low light conditions, their growth rate was significantly reduced as compared with the wild-type, due to a lowered efficiency of the light reaction of photosynthesis. We show that this phenotype is caused by the deficiency in a pigment–protein complex of the light-harvesting antenna of photosystem II and hence by a reduced efficiency of photon capture when light availability is limiting. Our results indicate that, in contrast to the current view, light-harvesting complexes do not only consist of the classical pigment-binding proteins, but may contain small structural subunits in addition. These subunits appear to be crucial architectural factors for the assembly and/or maintenance of stable light-harvesting complexes

Reden zum Abschied von Herrn Kirchgäßner

gehalten von:- Marion Mallmann-Biehler;- Monika Moravetz-Kuhlmann;- Susanne Göttker;- Ulrike Rothe;- Anne Bein;- Klaus Bahmann;- Gerrit Schmitz-Velit

Computereinsatz im Mathematikunterricht: Nutzung von interaktiver Werkzeugsoftware im Geometrie- und Stochastikunterricht

Die Studienwerkstatt Mathematik in den Sekundarstufen richtet sich an Studierende und Lehrer und Lehrerinnen aus der Praxis. Schwerpunkt der verfügbaren Materialien, der laufenden Projekte und Fortbildungsangebote ist der Einsatz von Computern und IT im Mathematikunterricht. Ein Netzwerk mit Schulen ist im Aufbau, schulpraktische Studien von Studierenden werden mit forschendem Lernen und Unterrichtsentwicklung an den beteiligten Schulen verknüpft. (DIPF/Orig.

Standort Muenchen: soziooekonomische und raeumliche Strukturen der Neo-Industrialisierung

Available from Bibliothek des Instituts fuer Weltwirtschaft, ZBW, Duesternbrook Weg 120, D-24105 Kiel B 278733 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

A Stenotrophomonas maltophilia Multilocus Sequence Typing Scheme for Inferring Population Structure▿ †

Stenotrophomonas maltophilia is an opportunistic, highly resistant, and ubiquitous pathogen. Strains have been assigned to genogroups using amplified fragment length polymorphism. Hence, isolates of environmental and clinical origin predominate in different groups. A multilocus sequence typing (MLST) scheme was developed using a highly diverse selection of 70 strains of various ecological origins from seven countries on all continents including strains of the 10 previously defined genogroups. Sequence data were assigned to 54 sequence types (ST) based on seven loci. Indices of association for all isolates and clinical isolates of 2.498 and 2.562 indicated a significant linkage disequilibrium, as well as high congruence of tree topologies from different loci. Potential recombination events were detected in one-sixth of all ST. Calculation of the mean divergence between and within predicted clusters confirmed previously defined groups and revealed five additional groups. Consideration of the different ecological origins showed that 18 out of 31 respiratory tract isolates, including 12 out of 19 isolates from cystic fibrosis (CF) patients, belonged to genogroup 6. In contrast, 16 invasive strains isolated from blood cultures were distributed among nine different genogroups. Three genogroups contained isolates of strictly environmental origin that also featured high sequence distances to other genogroups, including the S. maltophilia type strain. On the basis of this MLST scheme, isolates can be assigned to the genogroups of this species in order to further scrutinize the population structure of this species and to unravel the uneven distribution of environmental and clinical isolates obtained from infected, colonized, or CF patients

Plasmid-Mediated Quinolone Resistance in Isolates Obtained in German Intensive Care Units

Screening of 703 isolates of Enterobacteriaceae, obtained from 34 German intensive care units (ICUs), revealed qnr-positive, integron-containing isolates of Enterobacter sp. and Citrobacter freundii from four patients in 2 German ICUs. This is one of the first reports of qnr-positive strains obtained from patients in Europe

Limitation in Electron Transfer in Photosystem I Donor Side Mutants of <i>Chlamydomonas reinhardtii</i>: lethal photo-oxidative damage in high light is overcome in a suppressor strain deficient in the assembly of the light harvesting complex

Strains of Chlamydomonas reinhardtiilacking the PsaF gene or containing the mutation K23Q within the N-terminal part of PsaF are sensitive to high light (>400 μE m⁻² s⁻¹) under aerobic conditions.In vitro experiments indicate that the sensitivity to high light of the isolated photosystem I (PSI) complex from wild type and from PsaF mutants is similar. In vivo measurements of photochemical quenching and oxygen evolution show that impairment of the donor side of PSI in the PsaF mutants leads to a diminished linear electron transfer and/or a decrease of photosystem II (PSII) activity in high light. Thermoluminescence measurements indicate that the PSII reaction center is directly affected under photo-oxidative stress when the rate of electron transfer becomes limiting in the PsaF-deficient strain and in the PsaF mutant K23Q. We have isolated a high light-resistant PsaF-deficient suppressor strain that has a high chlorophyll a/b ratio and is affected in the assembly of light-harvesting complex. These results indicate that under high light a functionally intact donor side of PSI is essential for protection of C. reinhardtii against photo-oxidative damage when the photosystems are properly connected to their light-harvesting antennae

Hop Extract Acts as an Antioxidant with Antimicrobial Effects against Propionibacterium Acnes and Staphylococcus Aureus

Acne is associated with hyperkeratosis, elevated levels of skin sebum and growth of Propionibacterium acnes (P. acnes) and Staphylococcus aureus (S. aureus). Furthermore, P. acnes promotes inflammation by inducing IL-6 production and oxidative stress. The aim of this study was to assess the antioxidant, anti-inflammatory and antibacterial potential of a hop-CO2-extract with 50% humulone and lupulone. The susceptibility of P. acnes and S. aureus to the hop extract was tested by using the broth microdilution technique. The minimal inhibitory concentrations (MIC) for P. acnes and S. aureus were 3.1 and 9.4 &micro;g/mL, respectively. In addition, the hop extract showed an antioxidative effect with a half maximal inhibitory concentration (IC50) of 29.43 &micro;g/mL as well as additional anti-inflammatory effects by reducing the IL-6 expression (IC50: 0.8 &micro;g/mL). In addition, a gel formulation with 0.3% hop extract (w/w) had antibacterial activity against P. acnes and S. aureus (inhibition zone value: 5.5 mm and 3 mm, respectively) which was significantly superior to the placebo gel. The positive control (a gel with the antibiotic clindamycin) showed an inhibition zone of 9 mm. Due to its antioxidant, anti-inflammatory and antibacterial effects hop extract might be a treatment option for acne-prone skin

Review of Literature for Air Medical Evacuation High-Level Containment Transport

Introduction Aeromedical evacuation (AE) is a challenging process, further complicated when a patient has a highly hazardous communicable disease (HHCD). We conducted a review of the literature to evaluate the processes and procedures utilized for safe AE high-level containment transport (AE-HLCT) of patients with HHCDs. Methods A literature search was performed in PubMed/MEDLINE (from 1966 through January 2019). Authors screened abstracts for inclusion criteria and full articles were reviewed if the abstract was deemed to contain information related to the aim. Results Our search criteria yielded 14 publications and were separated based upon publication dates, with the natural break point being the beginning of the 2013-2016 Ebola virus disease epidemic. Best practices and recommendations from identified articles are subdivided into pre-flight preparations, inflight operations, and post-flight procedures. Conclusions Limited peer-reviewed literature exists on AE-HLCT, including important aspects related to healthcare worker fatigue, alertness, shift scheduling, and clinical care performance. This hinders the sharing of best practices to inform evacuations and equip teams for future outbreaks. Despite the successful use of different aircraft and technologies, the unique nature of the mission opens the opportunity for greater coordination and development of consensus standards for AE-HLCT operations