Slurry-grown duckweed (Spirodela polyrhiza) as a means to recycle nitrogen into feed for rainbow trout fry

Liquid manure from livestock production systems is a major source of nitrogen and phosphorus release from nutrient cycles and a cause of ecosystem eutrophication. Duckweeds, small aquatic plants, may be used to recover N and P from livestock slurry while producing high-quality protein feed. In order to assess N and P uptake efficiency and utility for fish feed, two duckweed species, Landoltia punctata and Spirodela polyrhiza, were grown in controlled climate chambers on two nutrient-rich media: diluted (1:10) cattle slurry and mechanically filtered household sewage. Treatments were in triplicate, each running in four cycles with fresh substrate (one week each). Spirodela polyrhiza exhibited the strongest growth (96 g fresh matter m−2 day−1) and highest protein content (306 g per kg dry matter) on diluted slurry. The weakest growth was found for L. punctata on treated sewage (52 g fresh matter m−2 day−1). Average removal of total provided and utilizable inorganic N from the media was 73.2% and 83.9% for sewage and diluted slurry, respectively. Spirodela polyrhiza grown on diluted slurry was subsequently tested as feed ingredient for rainbow trout (Oncorhynchus mykiss) fry. Two different ingredient levels of S. polyrhiza meal (6.25% and 12.5% of feed) were fed to rainbow trout fry for 4 weeks, during which fish growth, feed and nutrient utilization and gut health were assessed. Feed was accepted, but both duckweed meal treatments resulted in 5–10% poorer growth traits and feed efficiency compared to control. The intestine somatic index was not affected. This is the first time the potential of duckweed as feed for rainbow trout fry has been demonstrated. Furthermore, our experiments found considerable N and P uptake from diluted slurry by S. polyrhiza, which produced protein at a high rate per unit time and area

Cooperating Mechanisms of CXCR5 and CCR7 in Development and Organization of Secondary Lymphoid Organs

Homeostatic chemokines participate in the development of secondary lymphoid organs and later on in the functional organization of these tissues. The development of lymph nodes (LNs) and Peyer's patches depends on the recruitment of CD3− CD4+ interleukin (IL)-7Rαhi cells to sites of future organ development. CD3− CD4+ IL-7Rαhi cells express the chemokine receptor CXCR5 and might be attracted by its ligand CXCL13, which is secreted by mesenchymal cells. Mesenchymal cells also secrete CCL19, a ligand for CCR7, yet it is not clear whether CCR7 and CCL19 are important for secondary lymphoid organ development. Analyzing CXCR5−/− CCR7−/− double deficient mice we now show that these mice lack all examined peripheral LNs suggesting a profound role for both receptors in secondary lymphoid organ development. We demonstrate that CD3− CD4+ IL-7Rαhi cells express CXCR5 as well as CCR7 indicating that both receptors cooperate during an early step of secondary lymphoid organ development. Furthermore, CXCR5−/− CCR7−/− mice display a severely disturbed architecture of mesenteric LN and spleen. Due to an impaired migration of B cells into the white pulp, CXCR5−/− CCR7−/− mice fail to develop B cell follicles but show small clusters of unorganized lymphocytes in the spleen. These data demonstrate a cooperative function of CXCR5 and CCR7 in lymphoid organ organogenesis and organization

Aufruf zum Trialog für räumliche Transformation : von der Projektpartnerschaft zum strategischen Lern- und Handlungsfeld

Die nachhaltigkeitsorientierte Transformation von urbanen Räumen ist eine akute Herausforderung. In den letzten Jahren haben koproduktive, experimentelle, transdisziplinäre und häufig informelle Stadtwandelprojekte als Such- und Lösungsräume hohe Sichtbarkeit erlangt. Schlüsselakteure hierfür stellen - so die These - Verwaltungsvertreter:innen einer integrierten Stadtentwicklung und -planung, Wissenschaftler:innen einer transformativen Forschung sowie zivilgesellschaftliche Stadtmacher:innen dar. Die Autor:innen, verankert in diesen drei Gruppen, kritisieren die häufig nur situative Zusammenarbeit dieser drei Akteursgruppen. Ein Modell der Zusammenarbeit im Spannungsfeld zwischen Gemeinsamkeiten, jeweiligen Potentialen und herausfordernden Eigenlogiken der Akteurssysteme wird entwickelt. Darauf aufbauend wird vorgestellt, wie durch strategischen Trialog und reflexive Lernprozesse die Zusammenarbeit verbessert und die Wirksamkeit koproduktiven und experimentellen Stadtwandels erhöht werden kann

Crystallization and preliminary X-ray diffraction analysis of an Escherichia coli tRNAGly acceptor-stem microhelix

In order to investigate the identity elements of the E. coli tRNAGly/GlyRS class II system, a tRNAGly acceptor-stem microhelix was crystallized and a data set was collected to 2.0 Å resolution using synchrotron radiation

Cocrystallizing natural RNA with its unnatural mirror image: biochemical and preliminary X-ray diffraction analysis of a 5S rRNA A-helix racemate

A 5S rRNA A-helix 7-mer oligonucleotide was chemically synthesized both as d-RNA and as l-RNA, biochemically investigated, crystallized as a stochiometric racemate and examined by X-ray diffraction

Crystallization and preliminary X-ray diffraction analysis of a tRNASer acceptor-stem microhelix

In order to investigate tRNA identity elements, an elongator tRNASer acceptor-stem helix was crystallized and a data set was collected to 1.8 Å resolution aiming at a comparison with the corresponding region in suppressor tRNASec

Validation of the Asthma Severity Scoring System (ASSESS) in the ALLIANCE cohort.

BACKGROUND The Asthma Severity Scoring System (ASSESS) quantifies asthma severity in adolescents and adults. Scale performance in children < 12 years is unknown. OBJECTIVE To validate the ASSESS score in the All Age Asthma Cohort (ALLIANCE) and explore its use in children <12 years. METHODS Scale properties, responsiveness, and known-group validity were assessed in 247 children (median age 11 years, IQR: 8-13 years) and 206 adults (median age 52 years, IQR: 43-63 years). RESULTS Overall, measures of internal test consistency and test-retest reliability were similar to the original data of the Severe Asthma Research Program (SARP). Cronbach's α was 0.59 in children 12-18 years and 0.73 in adults, reflecting the inclusion of multiple and not always congruent dimensions to the ASSESS score especially in children. Analysis of known-group validity confirmed the discriminatory power, as the ASSESS score was significantly worse in patients with poor asthma control, exacerbations and increased salbutamol use. In children between 6-11 years test reliability was inferior compared to adults and adolescents (Cronbach's α 0.27) mostly due to a less lung function impairment in asthmatic children of this age group. Known-group validity however confirmed good discriminative power regarding severity-associated variables similar to adolescents and adults. CONCLUSION Test reliability and validity of the ASSESS score was confirmed in the ALLIANCE cohort. In children aged 6-11 years internal consistency was inferior compared to older asthma patients, however test validity was good and encourages age-spanning usage of the ASSESS score in all asthma patients ≥ 6 years