Comparison of different droplet measurement techniques in the Braunschweig Icing Wind Tunnel

The generation, transport and characterization of supercooled droplets in multiphase wind tunnel test facilities is of great importance for conducting icing experiments and to better understand cloud microphysical processes such as coalescence, ice nucleation, accretion and riming. To this end, a spray system has been developed, tested and calibrated in the Braunschweig Icing Wind Tunnel. Liquid droplets in the size range of 1 to 150 µm produced by pneumatic atomizers were accelerated to velocities between 10 and 40 m s−1 and supercooled to temperatures between 0 and −20 ∘C. Thereby, liquid water contents between 0.07 and 2.5 g m−3 were obtained in the test section. The wind tunnel conditions were stable and reproducible within 3 % standard variation for median volumetric diameter (MVD) and 7 % standard deviation for liquid water content (LWC). Different instruments were integrated in the icing wind tunnel measuring the particle size distribution (PSD), MVD and LWC. Phase Doppler interferometry (PDI), laser spectroscopy with a fast cloud droplet probe (FCDP) and shadowgraphy were systematically compared for present wind tunnel conditions. MVDs measured with the three instruments agreed within 15 % in the range between 8 and 35 µm and showed high coefficients of determination (R2) of 0.985 for FCDP and 0.799 for shadowgraphy with respect to PDI data. Between 35 and 56 µm MVD, the shadowgraphy data exhibit a low bias with respect to PDI. The instruments' trends and biases for selected droplet conditions are discussed. LWCs determined from mass flow calculations in the range of 0.07–1.5 g m−3 are compared to measurements of the bulk phase rotating cylinder technique (RCT) and the above-mentioned single-particle instruments. For RCT, agreement with the mass flow calculations of approximately 20 % in LWC was achieved. For PDI 84 % of measurement points with LWC<0.5 g m−3 agree with mass flow calculations within a range of ±0.1 g m−3. Using the different techniques, a comprehensive wind tunnel calibration for supercooled droplets was achieved, which is a prerequisite for providing well-characterized liquid cloud conditions for icing tests for aerospace, wind turbines and power networks

Chilling tolerance in soybeans (Glycine max) – a prerequisite for soybean cultivation in Germany

Über die Vorteile hinaus, die Leguminosen generell in der Fruchtfolge bieten, hat die Sojabohne (Glycine max (L.) Merr.) eine für die Ernährung von Mensch und Tier besonders günstige Proteinzusammensetzung. Aufgrund der nicht hinreichenden züchterischen Anpassung von Soja an unsere Klimaverhältnisse kann sie jedoch in Deutschland nur begrenzt angebaut werden. In diesem Zusammenhang ist die Kühletoleranz ein wichtiges Zuchtziel. Um Informationen über die genetische Variation bezüglich der Kühletoleranz zu gewinnen, wurde ein Test zur Erfassung des Hülsenansatzes unter Kühlestress etabliert, bei dem unter kontrollierten Bedingungen ab Blühbeginn 3 Wochen Kühlestress bei 15°C Tag/10°C Nacht appliziert wird. Dieser Test erwies sich als gut geeignet, um genotypische Unterschiede bezüglich des Hülsenansatzes unter Kühlestress reproduzierbar zu erfassen. Dabei wurde sowohl die Toleranz im engeren Sinne in Form eines wenig verminderten Hülsenansatzes unter Kühlestress gefunden, als auch Kompensationsvermögen in Form von vermehrtem Hülsenansatz nach der Kühlestressphase (Toleranz im weiteren Sinne) – bei einigen Genotypen ohne, bei anderen mit deutlicher Reifeverzögerung. Darüber hinaus gab es auch sensitive Genotypen ohne Kompensationsvermögen.Im Feldversuch 2011 und 2013 beobachtete Auswirkungen einer Kühlestressphase nach Blühbeginn auf den Hülsenansatz ergaben eine vergleichsweise gute Übereinstimmung mit den Ergebnissen aus dem Gefäßversuch unter kontrollierten Bedingungen. Die dreijährigen Feldversuche am Standort Groß Lüsewitz zeigten weiterhin, dass trotz der extrem nördlichen Lage des Standortes Soja erfolgreich in Norddeutschland angebaut werden kann, wenn entsprechend frühreife Sorten (frühe 00–0000) zum Einsatz kommen. Dabei stellte sich heraus, dass in Jahren mit höheren Wärmesummen die etwas späteren Sorten ihr meist höheres Ertragspotential realisieren konnten, über alle Jahre gesehen, die frühen Sorten auf einem etwas niedrigeren Ertragsniveau jedoch ertragsstabiler sind und ertragsstabile Sorten in der Regel auch über eine gute Kühletoleranz verfügen. DOI: 10.5073/JfK.2014.11.02, https://doi.org/10.5073/JfK.2014.11.02Besides advantages in crop rotations, soybeans are best suited for animal feed and human nutrition due to their protein content and composition. But, because of the limited adaptation to growing conditions, soybeans cannot be grown all over Germany mainly due to a lack of chilling tolerance, which is an important goal in soybean breeding in Germany therefore. In order to get information on the genetic variation of chilling tolerance in soybean, a test under controlled conditions was developed applying 15°C day/10°C night temperature for 3 weeks, which allows to get reliable information on pod set under cool conditions. Using this test, genotypes were identified revealing only a small reduction of the number of pods (chilling tolerance in the narrow sense), but also those compensating the loss of pods under cool conditions by a higher pod set in warmer conditions after the chilling period (tolerance in a broader sense). With respect to the latter also genotypic differences concerning the time to harvest were observed. Moreover, real sensitivity without compensation ability occurred. Responses of cultivars to a chilling period in the field trials of 2011 and 2013 showed a good correlation to the results obtained under controlled conditions. These field trials also demonstrated that soybean can be successfully grown even in Northern Germany, in case early ripening varieties (early 00–0000) are used. In this respect, higher yields of later ripening cultivars were observed in years with higher temperature sums while more stable yields but on a lower level were obtained by early ripening cultivars, where cultivars with high yield stability in general also showed a good chilling tolerance. DOI: 10.5073/JfK.2014.11.02, https://doi.org/10.5073/JfK.2014.11.0

Brief Sensory Deprivation Triggers Cell Type-Specific Structural and Functional Plasticity in Olfactory Bulb Neurons.

Can alterations in experience trigger different plastic modifications in neuronal structure and function, and if so, how do they integrate at the cellular level? To address this question, we interrogated circuitry in the mouse olfactory bulb responsible for the earliest steps in odor processing. We induced experience-dependent plasticity in mice of either sex by blocking one nostril for one day, a minimally invasive manipulation that leaves the sensory organ undamaged and is akin to the natural transient blockage suffered during common mild rhinal infections. We found that such brief sensory deprivation produced structural and functional plasticity in one highly specialized bulbar cell type: axon-bearing dopaminergic neurons in the glomerular layer. After 24 h naris occlusion, the axon initial segment (AIS) in bulbar dopaminergic neurons became significantly shorter, a structural modification that was also associated with a decrease in intrinsic excitability. These effects were specific to the AIS-positive dopaminergic subpopulation because no experience-dependent alterations in intrinsic excitability were observed in AIS-negative dopaminergic cells. Moreover, 24 h naris occlusion produced no structural changes at the AIS of bulbar excitatory neurons, mitral/tufted and external tufted cells, nor did it alter their intrinsic excitability. By targeting excitability in one specialized dopaminergic subpopulation, experience-dependent plasticity in early olfactory networks might act to fine-tune sensory processing in the face of continually fluctuating inputs.SIGNIFICANCE STATEMENT Sensory networks need to be plastic so they can adapt to changes in incoming stimuli. To see how cells in mouse olfactory circuits can change in response to sensory challenges, we blocked a nostril for just one day, a naturally relevant manipulation akin to the deprivation that occurs with a mild cold. We found that this brief deprivation induces forms of axonal and intrinsic functional plasticity in one specific olfactory bulb cell subtype: axon-bearing dopaminergic interneurons. In contrast, intrinsic properties of axon-lacking bulbar dopaminergic neurons and neighboring excitatory neurons remained unchanged. Within the same sensory circuits, specific cell types can therefore make distinct plastic changes in response to an ever-changing external landscape

Genomik-basierte Verbesserung des heimischen Sojazuchtmaterials und Etablierung eines molekularen Screeningsystems für Soja-Pathogene

Zur Einleitung von Pflanzenschutzmaßnahmen bei Soja ist es essentiell, Informationen über vorhandene Pathogene zu gewinnen. Basierend auf der quantitativen Real Time-PCR wurden Einzelnachweise für die Hauptpathogene der Sojabohne in Deutschland entwickelt. Die Pathogenität der Krankheitserreger wurde geprüft und das Inokulationsverfahren für weitere Untersuchungen etabliert. Erste Mehrfach-Nachweise für verschiedene Erreger und Probentypen wurden entwickelt, die für eine frühzeitige Detektion von Erregern in Soja-Proben (Saatgut, Pflanze, Boden) verwendet werden können. Im Rahmen des Projekts wurde zudem durch Kombination von aktuellen und zukünftigen Klimaparametern sowie Genotypisierungs- und Phänotypisierungsdaten eine Kernkollektion von Akzessionen erstellt, die sich durch eine hohe Diversität auszeichnet und sich für den Anbau unter den Bedingungen von Zentraleuropa eignet. Dabei wurden neue Gene für Umweltadaptation identifiziert, für die molekulare Marker für die Züchtung entwickelt werden, und geeignete Akzessionen für die Einkreuzung in aktuelle Züchtungsprogramme wurden selektiert. Die Ergebnisse zeigen außerdem klar, dass hochertragreiche Linien gezüchtet werden können, um die Sojaanbauregion nach Norden zu erweitern. Zudem bieten die gewonnenen Varianzkomponenten, Heritabilitäten und Merkmalskorrelationen eine solide Grundlage für die Gestaltung von Zuchtprogrammen, insbesondere auch von Speed-Breeding Programmen, die zukünftig mit genomischer und phänomischer Selektion beschleunigt werden können. Es wurden bereits erste Linien an die private Pflanzenzüchtung abgegeben, die in weiteren Prüfungen ermitteln, ob die Linien als Sorten zugelassen werden können. Gerade in kühleren Lagen, wie z.B. in Norddeutschland, ist die Gefahr von Ertragseinbußen auf Grund von Kühlestress groß. In diesem Projekt wurden Linien von Kreuzungsnachkommenschaften und ein diverses Set aus Genbankakzessionen hinsichtlich ihres Hülsenansatzes nach einer Kühlestressphase charakterisiert. Das Testsystem führte zu reproduzierbaren Ergebnissen und es wurden erste QTL für den Hülsenansatz unter Stressbedingungen ermittelt

Towards Palm-Size Autonomous Helicopters

muFly EU project started in 2006 with the idea to build an autonomous micro helicopter, comparable in size and weight to a small bird. Several scientific and technological objectives were identified. This spanned from system-level integration, high efficiency micro-actuation, highly integrated micro vision sensors and IMUs and also low processing power navigation algorithms. This paper shows how most of these objectives were reached, describing the approach and the role of each partner during the whole project. The paper describes also the technological developments achieved like the 80g, 17 cm micro robotic-helicopter, the 8g omnidirectional and steady-state laser scanner, the uIMU, the highly efficient micro motors, the high power-density fuel-cell and the successful graph-based navigation algorithm

Cell-free production of the bifunctional glycoside hydrolase GH78 from Xylaria polymorpha

The ability to catalyze diverse reactions with relevance for chemical and pharmaceutical research and industry has led to an increasing interest in fungal enzymes. There is still an enormous potential considering the sheer amount of new enzymes from the huge diversity of fungi. Most of these fungal enzymes have not been characterized yet due to the lack of high throughput synthesis and analysis methods. This bottleneck could be overcome by means of cell-free protein synthesis. In this study, cell-free protein synthesis based on eukaryotic cell lysates was utilized to produce a functional glycoside hydrolase (GH78) from the soft-rot fungus Xylaria polymorpha (Ascomycota). The enzyme was successfully synthesized under different reaction conditions. We characterized its enzymatic activities and immobilized the protein via FLAG-Tag interaction. Alteration of several conditions including reaction temperature, template design and lysate supplementation had an influence on the activity of cell-free synthesized GH78. Consequently this led to a production of purified GH78 with a specific activity of 15.4 U mg− 1. The results of this study may be foundational for future high throughput fungal enzyme screenings, including substrate spectra analysis and mutant screenings

A systematic mapping review of the evolution of the rat Forced Swim Test: Protocols and outcome parameters

As depression is projected to become the leading mental disease burden globally by 2030, understanding the underlying pathology, as well as screening potential anti-depressants with a higher efficacy, faster onset of action, and/or fewer side-effects is essential. A commonly used test for screening novel antidepressants and studying depression-linked aspects in rodents is the Porsolt Forced Swim Test. The present systematic mappping review gives a comprehensive overview of the evolution and of the most prevalently used set-ups of this test in rats, including the choice of animals (strain, sex, and age), technical aspects of protocol and environment, as well as reported outcome measures. Additionally, we provide an accessible list of all existing publications, to support informed decision-making for procedural and technical aspects of the test, to thereby enhance reproducibility and comparability. This should further contribute to reducing the number of unnecessarily replicated experiments, and consequently, reduce the number of animals used in future

Coupling aerosols to (cirrus) clouds in the global EMAC-MADE3 aerosol–climate model

A new cloud microphysical scheme including a detailed parameterization for aerosol-driven ice formation in cirrus clouds is implemented in the global ECHAM/MESSy Atmospheric Chemistry (EMAC) chemistry–climate model and coupled to the third generation of the Modal Aerosol Dynamics model for Europe adapted for global applications (MADE3) aerosol submodel. The new scheme is able to consistently simulate three regimes of stratiform clouds – liquid, mixed-, and ice-phase (cirrus) clouds – considering the activation of aerosol particles to form cloud droplets and the nucleation of ice crystals. In the cirrus regime, it allows for the competition between homogeneous and heterogeneous freezing for the available supersaturated water vapor, taking into account different types of ice-nucleating particles, whose specific ice-nucleating properties can be flexibly varied in the model setup. The new model configuration is tuned to find the optimal set of parameters that minimizes the model deviations with respect to observations. A detailed evaluation is also performed comparing the model results for standard cloud and radiation variables with a comprehensive set of observations from satellite retrievals and in situ measurements. The performance of EMAC-MADE3 in this new coupled configuration is in line with similar global coupled models and with other global aerosol models featuring ice cloud parameterizations. Some remaining discrepancies, namely a high positive bias in liquid water path in the Northern Hemisphere and overestimated (underestimated) cloud droplet number concentrations over the tropical oceans (in the extratropical regions), which are both a common problem in these kinds of models, need to be taken into account in future applications of the model. To further demonstrate the readiness of the new model system for application studies, an estimate of the anthropogenic aerosol effective radiative forcing (ERF) is provided, showing that EMAC-MADE3 simulates a relatively strong aerosol-induced cooling but within the range reported in the Intergovernmental Panel on Climate Change (IPCC) assessments

Differences in microphysical properties of cirrus at high and mid-latitudes

Despite their proven importance for the atmospheric radiative energy budget, the effect of cirrus on climate and the magnitude of their modification by human activity is not well quantified. Besides anthropogenic pollution sources on the ground, aviation has a large local effect on cirrus microphysical and radiative properties via the formation of contrails and their transition to contrail cirrus. To investigate the anthropogenic influence on natural cirrus, we compare the microphysical properties of cirrus measured at mid-latitude (ML) regions (&lt;60∘ N) that are often affected by aviation and pollution with cirrus measured in the same season in comparatively pristine high latitudes (HLs; ≥60∘ N). The number concentration, effective diameter, and ice water content of the observed cirrus are derived from in situ measurements covering ice crystal sizes between 2 and 6400 µm collected during the CIRRUS-HL campaign (Cirrus in High Latitudes) in June and July 2021. We analyse the dependence of cirrus microphysical properties on altitude and latitude and demonstrate that the median ice number concentration is an order of magnitude larger in the measured mid-latitude cirrus, with 0.0086 cm−3, compared to the high-latitude cirrus, with 0.001 cm−3. Ice crystals in mid-latitude cirrus are on average smaller than in high-latitude cirrus, with a median effective diameter of 165 µm compared to 210 µm, and the median ice water content in mid-latitude cirrus is higher (0.0033 g m−3) than in high-latitude cirrus (0.0019 g m−3). In order to investigate the cirrus properties in relation to the region of formation, we combine the airborne observations with 10 d backward trajectories to identify the location of cirrus formation and the cirrus type, i.e. in situ or liquid origin cirrus, depending on whether there is only ice or also liquid water present in the cirrus history, respectively. The cirrus formed and measured at mid-latitudes (M–M) have a particularly high ice number concentration and low effective diameter. This is very likely a signature of contrails and contrail cirrus, which is often observed in the in situ origin cirrus type. In contrast, the largest effective diameter and lowest number concentration were found in the cirrus formed and measured at high latitudes (H–H) along with the highest relative humidity over ice (RHi). On average, in-cloud RHi was above saturation in all cirrus. While most of the H–H cirrus were of an in situ origin, the cirrus formed at mid-latitudes and measured at high latitudes (M–H) were mainly of liquid origin. A pristine Arctic background atmosphere with relatively low ice nuclei availability and the extended growth of few nucleated ice crystals may explain the observed RHi and size distributions. The M–H cirrus are a mixture of the properties of M–M and H–H cirrus (preserving some of the initial properties acquired at mid-latitudes and transforming under Arctic atmospheric conditions). Our analyses indicate that part of the cirrus found at high latitudes is actually formed at mid-latitudes and therefore affected by mid-latitude air masses, which have a greater anthropogenic influence.</p