Wiederansiedlung seltener und gefährdeter Ackerwildpflanzen auf Ökobetrieben. Teilprojekt Witzenhausen: Versuche auf Praxisbetrieben

Abundance and diversity of arable weeds have been strongly declining in many European regions. Arable weeds are highly dependent on the respective type of management, and thus future programs for conservation of rare arable weeds have to establish a close and innovative integration with sustainable farming practice. The project “Restoration of local populations of rare and endangered arable field plants on organic farms in Germany” aims at developing applied scientific knowledge on new methods for conservation of arable weeds within farming systems. Two complementary research teams in contrasting regions in Germany test different approaches to reestablish arable weeds under various management systems and with different preconditions. The research team of the University of Kassel investigates the transfer of remnant populations of the species from nearby populations to organic fields. Two methods are being tested: the transplantation via seeds and the transplantation via transfer of surface soil

Entwicklung von Verfahren zur Wiederansiedlung gefährdeter Ackerwildpflanzen auf ökologisch bewirtschafteten Äckern

Ökologischer Ackerbau kann zur Erhaltung gefährdeter Ackerwildkräuter beitragen. Im Rahmen des Projekts "Wiederansiedlung seltener und gefährdeter Ackerwildpflanzen naturräumlicher Herkünfte auf Biobetrieben” werden Methoden zur Reetablierung von Ackerwildkräutern auf Feldern geringer Diversität erprobt, die bspw. aufgrund konventioneller Vorbewirtschaftung mit Herbizien floristisch verarmt sind. Verschiedene Übertragungsmethoden (Saatgut, Oberboden) werden erprobt. Vorgestellt werden Versuchsergebnisse zur Etablierung der Arten aus den ersten zwei Versuchsjahren. Beide Übertragungstechniken sind erfolgreich

Staphylococcus aureus proteins Sbi and Efb recruit human plasmin to degrade complement C3 and C3b

Upon host infection, the human pathogenic microbe Staphylococcus aureus (S. aureus) immediately faces innate immune reactions such as the activated complement system. Here, a novel innate immune evasion strategy of S. aureus is described. The staphylococcal proteins surface immunoglobulin-binding protein (Sbi) and extracellular fibrinogen-binding protein (Efb) bind C3/C3b simultaneously with plasminogen. Bound plasminogen is converted by bacterial activator staphylokinase or by host-specific urokinase-type plasminogen activator to plasmin, which in turn leads to degradation of complement C3 and C3b. Efb and to a lesser extend Sbi enhance plasmin cleavage of C3/C3b, an effect which is explained by a conformational change in C3/C3b induced by Sbi and Efb. Furthermore, bound plasmin also degrades C3a, which exerts anaphylatoxic and antimicrobial activities. Thus, S. aureus Sbi and Efb comprise platforms to recruit plasmin(ogen) together with C3 and its activation product C3b for efficient degradation of these complement components in the local microbial environment and to protect S. aureus from host innate immune reactions

Utility of proximal plant sensors to support nitrogen fertilization in Chrysanthemum

Chrysanthemum morifolium Ramat. is a commonly grown ornamental worldwide. A proper timing of nitrogen (N) supply is essential for a qualitative crop and the return on investment for growers. Sub-optimal nitrogen nutrition negatively influences the commercial plant quality, while supra-optimal N has an environmental impact due to nitrate leaching. Therefore, (a) reliable indicator(s) of plant nitrogen status is/are needed. Two field-grown potted Chrysanthemum cultivars, 'Maya' and 'Orlando' were studied for three consecutive years (2016-2018). Three different N treatments were applied in order to obtain a variation in N content. Plant quality measurements consisted of plant height, diameter, leaf mass per area (2017 and 2018 only), biomass and foliar and plant N content analysis. Optical measurements were performed with a SPAD sensor (2016 and 2017) and a Dualex Scientific sensor (2017 and 2018) on leaf level and with a GreenSeeker NDVI meter on canopy level. Biomass, height and diameter tended to be smaller in the minimal fertilizer treatments. Leaf mass per area did influence the relation between N and chlorophyll measured with SPAD and Dualex. Epidermal polyphenolics measured with Dualex correlated better with foliar nitrogen than non-destructive chlorophyll measurements and the nitrogen balance index. Since abaxial epidermal polyphenolics were highly correlated with foliar nitrogen and convenient to measure in-field, we propose this measurement for decision support in Chrysanthemum fertilization. Because of cultivar and sometimes year-to-year variability, reference plots can be of help for growers and advisors. NDVI was found to be more susceptible for yearly variation, but very high correlation with several quality parameters and convenience in use make this vegetation index useful for detecting the extent of spatial quality variability and thus support site dependent N requirements to reach the desired plant diameter at the end of the growing season

Humusgehalt und -qualität nach 28 Jahren Aushagerung im Vergleich zu ausreichend mit Stickstoff versorgtem Boden im statischen Stickstoffdüngungsversuch der TH Bingen

Die Stabilisierung der organischen Substanz im Boden, sei es durch Mineralassoziierung oder durch zunehmende Rekalzitranz geht mit einer Verengung des C:N-Verhältnisses einher. Chronischer N-Mangel könnte deshalb langfristig die Stabilisierung des Humus im Boden beeinträchtigen. Um dieser Frage nachzugehen, wurden aus den oberen 10 cm des statischen N-Düngungsversuch der TH Bingen Bodenproben entnommen und auf leicht mineralisierbaren, leicht hydrolysierbaren sowie auf partikulären (POM) und mineralassoziierten (MAOM) organischen N und C untersucht. Das Aushagern durch langjährig unterlassene Stickstoffdüngung führte zu einem Rückgang des Humusgehalts im Boden. Von dem aushagerungsbedingten Rückgang der orga-nischen Substanz waren allerdings nicht alle Humus-Fraktionen gleichermaßen betroffen. Relativ am stärk¬sten spiegelte sich die Aushagerung in der hydrolysierbaren Fraktion wider, was am heißwasserlöslichen Stickstoff erkennbar wurde (minus 27,2% bzw. 26,5 %). Auch der potenziell mineralisierbare N war von der Aushagerung besonders stark betroffen. Mit minus 19,6% bzw. 21,9 % reagierte die partikulare organische Substanz (POM) zwar deutlich stärker als die mineralassoziierte Fraktion (minus 8,6% bzw. 9,9%). Die POM-Fraktion war damit jedoch weniger sensitiv hinsichtlich Aushagerung als die hydrolysierbare N-Fraktion. Dieser Befund stärkt die Vermutung, dass unter chronischem N-Mangel deutlich weniger hydrolysierbarer N im Boden akkumuliert, der für eine anschließende Stabilisierung zur Verfügung stehen könnte, als in Böden, die ausreichend mit Stickstoff versorgt werden

Application of proximal optical sensors to fine-tune nitrogen fertilization : opportunities for woody ornamentals

Today, high amounts of residual nitrogen are regularly being reported in the open field production of hardy nursery stock. In some cases, excessive fertilizers or side-dressings are applied when circumstances are not favorable for uptake. Aquatic as well as terrestrial ecosystems are sensitive to enrichment with nutrients, but growers also benefit when losses are avoided. In this study, the potential of proximal optical sensors to optimize nitrogen fertilization was investigated in four woody species: Acer pseudoplatanus L., Ligustrum ovalifolium Hassk., Prunus laurocerasus 'Rotundifolia' L. and Tilia cordata Mill. For three consecutive growing seasons, plants were grown under three different fertilization levels to generate different nitrogen contents. Plant growth and nitrogen uptake were monitored regularly and combined with sensor measurements including Soil Plant Analysis Development (SPAD), Dualex and GreenSeeker. Here, we show that optical sensors at the leaf level have good potential for assisting growers in the sustainable management of their nursery fields, especially if leaf mass per area is included. Nevertheless, care should be taken when plants with different leaf characteristics (e.g., wax-layer, color, and leaf thickness) are measured. When all measuring years were considered, high correlations (R-2 >= 0.80) were found between area-based foliar nitrogen content and its non-destructive proxy (i.e., chlorophyll)measured by Dualex or SPAD. Based on our results, we recommend a relative rather than absolute approach at the nursery level, as the number of species and cultivars produced is very diverse. Hence, knowledge of absolute threshold values is scarce. In this relative approach, a saturation index was calculated based on the sensor measurements of plants grown in a reference plot with an ample nitrogen supply

Clinical performance of the Elecsys electrochemiluminescent immunoassay for the detection of SARS-CoV-2 total antibodies

SCOPUS: le.jinfo:eu-repo/semantics/publishe

Clinical performance of the Panbio assay for the detection of SARS‐CoV‐2 IgM and IgG in COVID‐19 patients

Following the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, numerous serological tests have been developed, including rapid diagnostic tests. This study aims at assessing the clinical performance of the Panbio immunoglobulin G (IgG)/IgM coronavirus disease 2019 (COVID-19) test (Abbott), a rapid lateral flow assay for the qualitative detection of IgG and IgM against SARS-CoV-2. One hundred and thirty-eight samples from 95 COVID-19 patients with a positive SARS-CoV-2 reverse-transcriptase polymerase chain reaction were analyzed to assess the clinical sensitivity. Seventy-six pre-COVID-19 samples were used to evaluate the clinical specificity. Two independent and blinded raters determined visually the presence or absence of the IgG, IgM, and control lines for each test after 10 and 20 min. The sensitivity obtained from collected samples more than 14 days after the onset of symptoms was 95.2% for IgG. IgM was less frequently detected (highest sensitivity of 20.5%). The specificities obtained were 98.7% and 100% for IgG and IgM, respectively. In addition, the sensitivity of the assay was better when the reading was performed at 20 min than at 10 min, whereas the specificity was unchanged. The Panbio COVID-19 IgG/IgM rapid test detects IgG with high sensitivity 14 days since symptom onset but presents a low sensitivity for IgM. The specificity was excellent for both IgG and IgM.SCOPUS: ar.jinfo:eu-repo/semantics/publishe