Einfluss von Intensität und Zeitpunkt der Bodenbearbeitung auf Ertragsbildung von Weizen und N-Dynamik in Wasserschutzgebieten

Water protection is controlled by specific regulations in the German Federal States, e.g. the SchALVO in Baden-Württemberg. An amendment of the SchALVO demands, amongst others, a changed timing and intensity of soil tillage directly after growing crops with high-nitrogen residues. As Organic Farming highly relies on soil tillage for weed control, there is concern about decrease of yield and increase of weed infesta-tion in water protection areas if tillage is restricted. Field experiments were performed on practical farms with three treatments according to SchALVO (rigid tine cultivator or mouldboard plough for primary tillage, used in October, December or February) and two treatments according to best management practice (mouldboard plough in Octo-ber or November). The treatments were combined with growing either winter wheat or spring wheat, depending on the date of tillage. There were no significant differences between the SchALVO and the practice-related treatments for yield, yield parameters, protein content and weed infestation, whereas there were differences between the winter crop and spring crop. The total Nmin in soil was slightly lower in the SchALVO treatments. Here, Nmin reached 39 – 42 kg Nmin ha-1 (mean of the experimental years), compared to the practice-related treatments with 42 or 43 kg Nmin ha-1 in the sub-experiment exemplarily presented in this paper. These differences were not significant at P ≤ 0.05. Mean Nmin was 38.5 kg ha-1 before starting the experiment. The lowest Nmin was found after using a cultivator in October. Since the one-time use of a cultiva-tor instead of the plough did not result in obvious disadvantages for the crop, the risk of yield reduction and increased weed infestation seems to be small. Nevertheless, if the initial number of perennial weeds, e.g. thistles, is high, a plough is supposed to be more effective for weed control than non-inversion tillage by cultivator

Seasonal and spatial variability in plankton production and respiration in the Subtropical Gyres of the Atlantic Ocean

Euphotic zone plankton production (P) and respiration (R) were determined from the in vitro flux of dissolved oxygen during six latitudinal transects of the Atlantic Ocean, as part of the Atlantic Meridional Transect (AMT) programme. The transects traversed the North and South Atlantic Subtropical Gyres (N gyre, 18–38°N; S gyre, 11–35°S) in April–June and September–November 2003–2005. The route and timing of the cruises enabled the assessment of the seasonal variability of P, R and P/R in the N and S gyres, and the comparison of the previously unsampled N gyre centre with the more frequently sampled eastern edge of the gyre. Mean euphotic zone integrated rates (±SE) were P=63±23 (n=31), R=69±22 (n=30) mmol O2 m-2 d-1 in the N gyre; and P=58±26 (n=30), R=62±24 (n=30) mmol O2 m-2 d-1 in the S gyre. Overall, the N gyre was heterotrophic (R>P) and it was more heterotrophic than the S gyre, but the metabolic balance of both gyres changed with season. Both gyres were net heterotrophic in autumn, and balanced in spring. This seasonal contrast was most pronounced for the S gyre, because it was more autotrophic than the N gyre during spring. This may have arisen from differences in nitrate availability, because spring sampling in the S gyre coincided with periods of deep mixing to the nitracline, more frequently than spring sampling within the N gyre. Our results indicate that the N gyre is less heterotrophic than previous estimates suggested, and that there is an apparent decrease in R from the eastern edge to the centre of the N gyre, possibly indicative of an allochthonous organic carbon source to the east of the gyre

Predicting plankton net community production in the Atlantic Ocean

We present, test and implement two contrasting models to predict euphotic zone net community production (NCP), which are based on 14C primary production (PO14CP) to NCP relationships over two latitudinal (ca. 30°S–45°N) transects traversing highly productive and oligotrophic provinces of the Atlantic Ocean (NADR, CNRY, BENG, NAST-E, ETRA and SATL, Longhurst et al., 1995 [An estimation of global primary production in the ocean from satellite radiometer data. Journal of Plankton Research 17, 1245–1271]). The two models include similar ranges of PO14CP and community structure, but differ in the relative influence of allochthonous organic matter in the oligotrophic provinces. Both models were used to predict NCP from PO14CP measurements obtained during 11 local and three seasonal studies in the Atlantic, Pacific and Indian Oceans, and from satellite-derived estimates of PO14CP. Comparison of these NCP predictions with concurrent in situ measurements and geochemical estimates of NCP showed that geographic and annual patterns of NCP can only be predicted when the relative trophic importance of local vs. distant processes is similar in both modeled and predicted ecosystems. The system-dependent ability of our models to predict NCP seasonality suggests that trophic-level dynamics are stronger than differences in hydrodynamic regime, taxonomic composition and phytoplankton growth. The regional differences in the predictive power of both models confirm the existence of biogeographic differences in the scale of trophic dynamics, which impede the use of a single generalized equation to estimate global marine plankton NCP. This paper shows the potential of a systematic empirical approach to predict plankton NCP from local and satellite-derived P estimates

Politique d’éducation et évolution de l’école en Autriche

Contrairement à la Suède, à la Finlande, aux Pays-Bas et à l’Australie, l’Autriche ne fait pas partie des pays de l’OCDE réputés pour leur propension à l’innovation et pour donner des impulsions novatrices à l’évolution internationale des systèmes scolaires. Bien au contraire, tout comme l’Allemagne et la Suisse alémanique, l’Autriche fait figure de « village gaulois » qui résiste à la réforme et dont la caractéristique fondamentale est le maintien de la différenciation du premier degré de l’..

"Real" and pseudo comprehensive schools. A sketch of the Europe-wide implementation of reforms of the lower secondary educational system during the last forty years, including some remarks about the reform discourse in Germany and Austria

Während die Mehrzahl der europäischen Länder in den vergangenen Jahrzehnten die traditionelle ("alteuropäische"), selektive, mehrgliedrige Sekundarstufe I durch Gesamtschulsysteme ersetzt hat, halten Deutschland und Österreich am euphemistisch "gegliedert" genannten Schulsystem fest. Die deutschen Gesamtschulen entsprechen nicht den Kriterien, die für diese Schulform gelten, und müssen daher als Pseudo-Gesamtschulen bezeichnet werden. Der Vorschlag, die deutsche Mehrgliedrigkeit durch Zweigliedrigkeit zu ersetzen, dürfte angesichts der Probleme des seit Jahrzehnten existierenden zweigliedrigen österreichischen Schulsystems wenig erfolgversprechend sein. (DIPF/Orig.)While the majority of the European countries has replaced the traditional ("old European"), selective, subdivided lower secondary educational system by comprehensive schools during the last decades, Germany and Austria cling to the euphemistically so-called "subdivided" system. German comprehensive schools do not meet the criteria which have been established for this type of school and must therefore be called "pseudo"-comprehensive schools. The proposal to replace the German system by a binary one will be hardly promising if one regards the problems of the Austrian school system which has already been binary for decades.(DIPF/Orig.

Doubling of marine dinitrogen-fixation rates based on direct measurements

Biological dinitrogen fixation provides the largest input of nitrogen to the oceans, therefore exerting important control on the ocean’s nitrogen inventory and primary productivity. Nitrogen-isotope data fromocean sediments suggest that the marine-nitrogen inventory has been balanced for the past 3,000 years (ref. 4). Producing a balanced marine-nitrogenbudget based on direct measurements has proved difficult, however, with nitrogen loss exceeding the gain from dinitrogen fixation by approximately 200 TgNyr-1 (refs 5, 6). Here we present data from the Atlantic Ocean and show that the most widely used method of measuring oceanic N2-fixation rates underestimates the contribution of N2-fixing microorganisms (diazotrophs) relative to a newly developed method. Using molecular techniques to quantify the abundance of specific clades of diazotrophs in parallel with rates of 15N2 incorporation into particulate organic matter, we suggest that the difference between N2-fixation rates measured with the established method and those measured with the new method8 can be related to the composition of the diazotrophic community. Our data show that in areas dominated by Trichodesmium, the established method underestimatesN2-fixation rates by an averageof 62%. We also find that the newly developed method yields N2-fixation rates more than six times higher than those from the established method when unicellular, symbiotic cyanobacteria and c-proteobacteria dominate the diazotrophic community. On the basis of average areal rates measured over the Atlantic Ocean, we calculated basin-wide N2-fixation rates of 14+/-1TgNyr-1 and 24+/-1TgNyr-1 for the established and new methods, respectively. If our findings can be extrapolated to other ocean basins, this suggests that the global marine N2-fixation rate derived from direct measurements may increase from 103+/-8TgNyr-1 to 177+/-8TgNyr-1, and that the contribution of N2 fixers other than Trichodesmium is much more significant than was previously thought

Immunization in pregnancy clinical research in low- and middle-income countries - Study design, regulatory and safety considerations.

Immunization of pregnant women is a promising public health strategy to reduce morbidity and mortality among both the mothers and their infants. Establishing safety and efficacy of vaccines generally uses a hybrid design between a conventional interventional study and an observational study that requires enrolling thousands of study participants to detect an unknown number of uncommon events. Historically, enrollment of pregnant women in clinical research studies encountered many barriers based on risk aversion, lack of knowledge, and regulatory ambiguity. Conducting research enrolling pregnant women in low- and middle-income countries can have additional factors to address such as limited availability of baseline epidemiologic data on disease burden and maternal and neonatal outcomes during and after pregnancy; challenges in recruiting and retaining pregnant women in research studies, variability in applying and interpreting assessment methods, and variability in locally acceptable and available infrastructure. Some measures to address these challenges include adjustment of study design, tailoring recruitment, consent process, retention strategies, operational and logistical processes, and the use of definitions and data collection methods that will align with efforts globally

Iron and phosphorus co-limit nitrogen fixation in the eastern tropical North Atlantic

The role of iron in enhancing phytoplankton productivity in high nutrient, low chlorophyll oceanic regions was demonstrated first through iron-addition bioassay experiments1 and subsequently confirmed by large-scale iron fertilization experiments2. Iron supply has been hypothesized to limit nitrogen fixation and hence oceanic primary productivity on geological timescales3, providing an alternative to phosphorus as the ultimate limiting nutrient4. Oceanographic observations have been interpreted both to confirm and refute this hypothesis5, 6, but direct experimental evidence is lacking7. We conducted experiments to test this hypothesis during the Meteor 55 cruise to the tropical North Atlantic. This region is rich in diazotrophs8 and strongly impacted by Saharan dust input9. Here we show that community primary productivity was nitrogen-limited, and that nitrogen fixation was co-limited by iron and phosphorus. Saharan dust addition stimulated nitrogen fixation, presumably by supplying both iron and phosphorus10, 11. Our results support the hypothesis that aeolian mineral dust deposition promotes nitrogen fixation in the eastern tropical North Atlantic

Recent changes in the mutational dynamics of the SARS-CoV-2 main protease substantiate the danger of emerging resistance to antiviral drugs

IntroductionThe current coronavirus pandemic is being combated worldwide by nontherapeutic measures and massive vaccination programs. Nevertheless, therapeutic options such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main-protease (Mpro) inhibitors are essential due to the ongoing evolution toward escape from natural or induced immunity. While antiviral strategies are vulnerable to the effects of viral mutation, the relatively conserved Mpro makes an attractive drug target: Nirmatrelvir, an antiviral targeting its active site, has been authorized for conditional or emergency use in several countries since December 2021, and a number of other inhibitors are under clinical evaluation. We analyzed recent SARS-CoV-2 genomic data, since early detection of potential resistances supports a timely counteraction in drug development and deployment, and discovered accelerated mutational dynamics of Mpro since early December 2021.MethodsWe performed a comparative analysis of 10.5 million SARS-CoV-2 genome sequences available by June 2022 at GISAID to the NCBI reference genome sequence NC_045512.2. Amino-acid exchanges within high-quality regions in 69,878 unique Mpro sequences were identified and time- and in-depth sequence analyses including a structural representation of mutational dynamics were performed using in-house software.ResultsThe analysis showed a significant recent event of mutational dynamics in Mpro. We report a remarkable increase in mutational variability in an eight-residue long consecutive region (R188-G195) near the active site since December 2021.DiscussionThe increased mutational variability in close proximity to an antiviral-drug binding site as described herein may suggest the onset of the development of antiviral resistance. This emerging diversity urgently needs to be further monitored and considered in ongoing drug development and lead optimization

Gold and biocatalysis for the stereodivergent synthesis of nor(pseudo)ephedrine derivatives: Cascade design toward amino alcohols, diols, and diamines

Financial support from the Spanish Ministry of Science and Innovation (MCI, PID2019-109253RB-I00) and the Asturian Regional Government (AYUD/2021/51542) are gratefully acknowledged. Technical support from the Scientific-Technical Services (UNIOVI) is acknowledged. We thank Prof. Wolfgang Kroutil (University of Graz, Austria) for providing us with alcohol dehydrogenases overexpressed in E. coli cells. S.G.-G. thanks the University of Oviedo for a predoctoral fellowship (PAPI-21-PF-14) inside the “Programa de Apoyo y Promoción de la Investigación”