ALBERT

Description: Construction of multiply mutated strains for genetic interaction analysis and of strains carrying different epitope tags at multiple open reading frames for testing protein localization, abundance and protein-protein interactions is hampered by the availability of a sufficient number of different selectable markers. Moreover, strains with single gene deletions or tags often already exist in strain collections; for historical reasons these will mostly carry the ura4 + gene or the G418-resistance kanMX as marker. Because it is rather cumbersome to produce multiply deleted or tagged strains using the same marker or to completely reconstruct a particular strain with a different marker, single-step exchange protocols of markers are a time-saving alternative. In recent years dominant drug resistance markers (DDRMs) against clonNAT, Hygromycin B, and Bleomycin have been adapted and successfully used in Schizosaccharomyces pombe . The corresponding DDRM cassettes – natMX , hphMX , and bleMX – all carry the TEF -promotor and -terminator sequences from Ashbya gossypii as kanMX , this provides flanking homologies to enable single-step marker swapping by homologous gene targeting. To expand this very useful toolset for single-step marker exchange I constructed MX -cassettes containing the nutritional markers arg3 + , his3 + , leu1 + , and ura4 + . Furthermore, a set of constructs was created to enable single-step exchange of ura4 + to kanMX6 , natMX4 , and hphMX4 . The functionality of the cassettes is demonstrated by successful single-step marker swapping at several loci. These constructs allow a straight-forward and rapid re-marking of existing ura4 + - and MX -deleted and -tagged strains.

Description: X-Ray diffractometry was employed to investigate the possibility of formation of non-equimolar discrete compounds in the chiral system of malic acid S - and R -enantiomers. Samples studied were mixtures of single enantiomers or an enantiomer and the various polymorphs of the racemic compound. From samples prepared via recrystallization of the melt and grinding of initial reactants, it is demonstrated that the malic acid enantiomers can form stable stoichiometric compounds in S : R ratios of 3:1 and 1:3. Compared to the known racemic and pure enantiomer phases, the corresponding compounds S 3 R / SR 3 are characterized by a proper powder diffraction pattern and melting point. Non-equimolar discrete compounds formed by malic acid S - and R -enantiomers in ratios 3:1 and 1:3 are investigated by means of X-ray powder diffraction. The corresponding S 3 R and SR 3 compounds are found to be stable or metastable phases in dependence on synthesis conditions. The phases are characterized and discussed with regard to their identity and crystallochemical nature.

Description: Phase formation, stability, crystal and electronic structures of IrPTe are investigated from experiment and quantum chemical calculations. The phase formation is studied from thermodynamic data and CalPhaD modeling. Applying a high-temperature gas-balance a formation pathway for IrPTe is studied from the elements and the binary parent compounds IrTe 2 and IrP 2 . The obtained paracostibite (CoSbS) type structure contains rarely occurring heteroatomic P–Te dumbbells. The stability of IrPTe and the found structure is studied from DFT calculations with respect to the elements, IrTe 2 and IrP 2 , and possible polymorphs. Probable metastable modifications with XY dumbbells (as known for isoelectronic compounds like CoAsS) are obtained from systematic DFT modelling. Phase transitions are predicted form the equation of states (EOS). According to its electronic band structure IrPTe is predicted as small gap (Δ E g = 0.5 eV) semiconductor.

Description: Despite of its ecological and economic importance, only limited information is available on spatial variability of soil organic C (OC) in paddy fields during soil development. To obtain deeper insights into the accumulation and spatial distribution of OC with ongoing paddy management, the present study investigates spatial heterogeneities in puddled topsoil layers, in the plough pan, as well as in the underlying subsoil of a 50- and 300-y old paddy site at the area of Cixi (Hangzhou Bay, E China). Sampling of the plots was done on the basis of a regular, orthogonal grid. The grid combined a large-scale design with distances of 5 m with a small-scale nested sampling ranging within 0.5 to 1 m. Samples have been taken with an auger in three sampling depths: (1) puddled topsoil layer, (2) dense plough layer, (3) mixed subsoil horizon. All samples were analyzed for their OC and total N concentrations as well as for their soil color (lightness value) to assess relationships between soil lightness and OC amount and distribution. The spatial behavior of all analyzed parameters in the different soil layers was investigated by calculating variograms; the degree of spatial dependence was determined by nugget-to-sill ratios. The results show that for each analyzed soil layer, OC and N concentrations were significantly higher in the field with 300 y of paddy management than in the field with 50 y of paddy management. Topsoil OC concentrations changed from 13.8 to 23.6 mg g −1 , OC in the plough layer changed from 3.3 to 9.6 mg g −1 , and also the subsoil showed a slight increase from 2.9 to 3.3 mg g −1 . Although only two points in time were compared, we assume that paddy soil formation is the most likely reason for differences in the spatial distribution of OC between the two sites. Comparing the spatial depth distribution of the 50- and 300-y old paddy sites suggests that the development of a spatial pattern of OC proceeded with time from topsoil to the underlying soil horizons. Measuring soil lightness was insufficient to predict amount and distribution of soil OC in paddy soils, especially in soils with interfering dark-colored burnt straw residues. The degree of spatial homogeneity was equal in the two sites, suggesting that cultivation practices (puddling, levelling, burning and incorporation of straw residues) most likely maintained a rather high random spatial variability of approx. 45%. The spatial pattern of OC in the topsoil was dissimilar to the plough layer, revealing that transport of OC in the plough pan occurred mainly in preferential flow paths along localized cracks and biopores.

Description: We examine how soil moisture variability and trends affect the simulation of temperature and precipitation extremes in six global climate models using the experimental protocol of the Global Land-Atmosphere Coupling Experiment of the Coupled Model Intercomparison Project, Phase 5 (GLACE-CMIP5). This protocol enables separate examinations of the influences of soil moisture variability and trends on the intensity, frequency and duration of climate extremes through to the end of the 21 s t century under a business-as-usual (RCP8.5) emission scenario. Removing soil moisture variability significantly reduces temperature extremes over most continental surfaces while wet precipitation extremes are enhanced in the tropics. Projected drying trends in soil moisture lead to increases in intensity, frequency, and duration of temperature extremes by the end of the 21 s t century. Wet precipitation extremes are decreased in the tropics with soil moisture trends in the simulations while dry extremes are enhanced in some regions, in particular the Mediterranean and Australia. However, the ensemble results mask considerable differences in the soil moisture trends simulated by the six climate models. We find that the large differences between the models in soil moisture trends, which are related to an unknown combination of differences in atmospheric forcing (precipitation, net radiation), flux partitioning at the land surface, and how soil moisture is parameterized, imply considerable uncertainty in future changes in climate extremes.

Description: A bstract Day-Dunlop plots are widely used in paleomagnetic and environmental studies as a tool to determine the magnetic domain state of magnetite, i.e., superparamagnetic (SP), stable single-domain (SD), pseudo-single-domain (PSD), multidomain (MD) and their mixtures. The few experimental studies that have examined hysteresis properties of SD-SP mixtures of magnetite found that the ratios of saturation remanent magnetization to saturation magnetization and the coercivity of remanence to coercivity are low, when compared to expected theoretical mixing trends based on Langevin theory. This study reexamines Day-Dunlop plots using experimentally controlled mixtures of SD and SP magnetite grains. End members include magnetotactic bacteria (MSR-1) as the SD source, and a commercial ferrofluid or magnetotactic bacteria (ΔA12) as the SP source. Each SP-component was added incrementally to a SD sample. Experimental results from these mixing series show that the magnetization and coercivity ratios are lower than the theoretical prediction for bulk SP magnetic size. Although steric repulsion was present between the particles we cannot rule out interaction in the ferrofluid for higher concentrations. The SP bacteria are non-interacting as the magnetite was enclosed by an organic bi-lipid membrane. Our results demonstrate that the magnetization and coercivity ratios of SD-SP mixtures can lie in the PSD range, and that an unambiguous interpretation of particle size can only be made with information about the magnetic properties of the end members. This article is protected by copyright. All rights reserved.

Description: Dust devils occur in arid climates on the Earth and ubiquitously on Mars, where they likely dominate the supply of atmospheric dust and influence climate. Martian dust devils have been studied with a combination of orbiting and landed spacecraft, while most studies of terrestrial dust devils have involved manned monitoring of field sites, which can be costly both in time and personnel. As an alternative approach, we describe a multi-year in-situ survey of terrestrial dust devils using pressureloggers deployed at El Dorado Playa in Nevada, USA, a site known for dust devil activity. Analogous to previous surveys for Martian dust devils, we conduct a post-hoc analysis of the barometric data to search for putative dust devil pressure dips usinga new automated detection algorithm. We investigate the completeness and false positive rates of our new algorithm and conduct several statistically robust analyses of the resulting population of dips. We also investigate possible seasonal, annual, and spatial variability of the putative dust devil dips, possible correlations with precipitation, and the influence of sample size on the derived population statistics. Our results suggest that large numbers of dips (〉 1,000) collected over multiple seasons are probably required for accurate assessment of the underlying dust devil population. Correlating long-term barometric time-series with other data streams (e.g., solar flux measurements from photovoltaic cells) can uniquely elucidate the natures and origins of dust devils, and accurately assessing their influence requires consideration of the full distribution of dust devil properties, rather than average values.

Description: We present a new approach to search for a subsurface ocean within Ganymede through observations and modeling of the dynamics of its auroral ovals. The locations of the auroral ovals oscillate due to Jupiter's time-varying magnetospheric field seen in the rest frame of Ganymede. If an electrically conductive ocean is present, the external time-varying magnetic field is reduced due to induction within the ocean and the oscillation amplitude of the ovals decreases. Hubble Space Telescope (HST) observations show that the locations of the ovals oscillate on average by 2.0° ± 1.3°. Our model calculations predict a significantly stronger oscillation by 5.8° ± 1.3° without ocean compared to 2.2°±1.3° if an ocean is present. Because the ocean and the no-ocean hypotheses cannot be separated by simple visual inspection of individual HST images, we apply a statistical analysis including a Monte-Carlo test to also address the uncertainty caused by the patchiness of observed emissions. The observations require a minimum electrical conductivity of 0.09 S/m for an ocean assumed to be located between 150 km and 250 km depth or alternatively a maximum depth of the top of the ocean at 330 km. Our analysis implies that Ganymede's dynamo possesses an outstandingly low quadrupole-to-dipole moment ratio. The new technique applied here is suited to probe the interior of other planetary bodies by monitoring their auroral response to time-varying magnetic fields.

Description: The complex dielectric constants of liquids methane and ethane were measured at 90 K and 14.1 GHz, close to the frequency of the Cassini RADAR. The liquid ethane loss tangent is far greater than that of liquid methane, facilitating discrimination by remote sensing. The results suggest a methane-dominated composition for the northern sea, Ligeia Mare, on the basis of a recent loss tangent determination using Cassini RADAR altimetry. This contrasts a previous far higher loss tangent for the southern lake, Ontario Lacus, which is inconsistent with simple mixtures of methane and ethane. The apparent non-equilibrium methane-to-ethane ratio of Ligeia Mare can be explained by poor admixture of periodically cycled methane with a deeper ethane-rich alkanofer system, consistent with obliquity-driven volatile cycling, sequestration of ethane from the hydrocarbon cycle by incorporation into crustal clathrate hydrates, or periodic flushing of Ligeia Mare into adjacent Kraken Mare by fresh rainfall.

Description: A 0-3 nanocomposite of CdSe (crystalline nanoparticles) and Cr 2 Se 3 (amorphous matrix) was synthesized via a soft chemical approach and characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Particularly the transformation of the 0-3 composite is explored in situ under electron beam irradiation and thermal annealing inside the TEM. In situ electron beam irradiation removed exclusively the CdSe nanoparticles and generated a porous Cr 2 Se 3 matrix with a slightly increased crystallinity. The highly localized beam heating and knock-on effect are attributed to the origin of the in situ irradiation transformation. During the in situ thermal annealing process of the 0-3 nanocomposite CdSe particles are eliminated and crystalline nano- and microparticles of Cr 2 Se 3 are generated. Also the formation of chromium enriched crystallites is observed. All of these in situ results are compared with conventional ex situ methods and discussed in terms of the different mechanisms associated with electron beam interaction and size effects of the nanocomposite.