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Dust emission fluxes during wind soil erosion are usually estimated using a dust concentration vertical gradient, by assuming a constant dust flux layer between the surface and the dust measurement levels. Here, we investigate the existence of this layer during erosion events recorded in Iceland and Jordan. Size‐resolved dust fluxes were estimated at three levels between 2 and 4 m using the eddy‐covariance method. Dust fluxes were found mainly constant only between the two upper levels in Iceland, the lower dust flux being often stronger and richer in coarse particles, while dust fluxes in Jordan were nearly constant across all levels. The wind dynamics could not explain the absence of a constant dust flux layer in Iceland. We show that the presence of stationary dust source patches in Iceland, related to surface humidity, created a non‐uniform dust layer near the surface, named dust roughness sublayer (DRSL), where individual plumes behind each patch interact but do not fully mix. The lowest dust measurement level was probably located within this sublayer while the upper ones were located above, such that there the emitted dust became spatially well‐mixed. This explains near the surface in Iceland, the more intermittent dust concentration, its low correlation with the dust concentrations above, and the richer dust flux in coarse particles due to their lower deposition contribution. Our findings highlight the importance of estimating dust fluxes above a dust blending height whose characteristics depend on the dust source patchiness caused by surface humidity or the presence of sparse non‐erosive elements. Plain Language Summary: During soil erosion by wind, dust flux from the surface is estimated at a few meters height, by assuming the existence of a constant dust flux layer between the surface and the dust measurement levels. Here, we investigated for the first time the existence of this layer during erosion events in Iceland and Jordan, by estimating the dust fluxes at three levels between 2 and 4 m height. In Iceland, the dust fluxes were constant only between the two upper levels. In Jordan, the dust fluxes remained constant across all levels. We demonstrates that the absence of a constant dust flux layer in Iceland is due to patches of stationary dust sources, which are related to surface humidity. These patches created a non‐uniform dust layer near the surface, known as the dust roughness sublayer. In this layer, individual plumes behind each patch interact but do not fully mix. The lowest dust measurement level was likely within this sublayer, while the upper measurements were located above it. Our findings highlight the importance of estimating dust fluxes above a dust blending height, which depends on the patchiness of the dust source caused by surface humidity or the presence of sparse non‐erosive elements. Key Points: Size‐resolved dust emission fluxes have been estimated for the first time at different heights during erosion events in Iceland and JordanUnlike in Jordan, the absence of a constant dust flux layer in Iceland is due to the dust source patchiness related to surface humidityOur results highlight the importance of estimating dust fluxes above a dust blending height that depends on the dust source patchiness [ABSTRACT FROM AUTHOR]

This case study examined student preference for delivery mode of online courses in two graduate degree programs in Library and Information Science. Within-group and between-groups comparisons indicated a distinct preference across the institutions. Findings from focus groups conducted with two cohorts of students enrolled in a federally funded project indicated students preferring asynchronous delivery enrolled in such courses to accommodate busy lifestyles. In the synchronously deployed course, flexibility in accommodation of various learning styles was evidenced by such influential factors as teaching style, instructional design, and topicality. Findings inform online education for modality and instructional style.

Agricultural fires affecting grass‐, crop‐ and shrublands represent a major, mainly anthropogenically driven disturbance of many ecosystems. In addition to emissions of carbonaceous aerosol, they were found to inject also mineral dust particles into the atmosphere. The fires can significantly modulate the near‐surface wind patterns so that conditions suitable for dust emission occur. However, the exact emission mechanism has not been investigated so far, but is inevitable for the understanding of its impacts on the Earth system. Here, we test two dust emission parameterizations representing saltation bombardment (SALT) and direct aerodynamic dust entrainment by (convective) turbulence (convective turbulent dust emission, CTDE) in the context of fire‐modulated wind patterns using large‐eddy simulation with an idealized setup to represent typical agricultural fire settings. Favorable aerodynamic preconditions for the initialization of both emission processes are found, however, with sometimes significant differences in dust emission flux depending on specific wind and fire properties. The strong fire‐induced modulations of the instantaneous momentum flux suggest that CTDE can be a very potent emission process in the fire vicinity. Nevertheless, fire impacts on the friction velocity can be significant too, so that dust emission through SALT is facilitated as well. Ultimately, the specific aerodynamic conditions within pyro‐convectively modulated wind patterns require the development of a parameterization that can describe these unique fire‐related dust emissions and their influencing factors properly. This will finally allow for considering fire‐induced dust emissions in aerosol‐atmosphere models and an investigation of its atmospheric impacts such as on the radiation budget. Plain Language Summary: Mineral dust particles are frequently observed within smoke plumes originating from agricultural fires of mostly semi‐arid regions. Such fires can modulate the near‐surface wind patterns and thus foster dust emission. However, the exact emission mechanism has not been investigated so far. Here, two conceptually different dust emission parameterizations are tested in the context of fire‐modulated wind patterns using high‐resolution model simulation. The results show that wind conditions favorable for the initialization of both processes occur, however, with partly substantial differences depending on the environmental preconditions. The direct entrainment of dust particles appears to be an important emission process, particularly under weak wind conditions, while another emission process including larger sand‐sized grains becomes more important under strong wind conditions. The unique fire‐related aerodynamic preconditions require the development of an adjusted parameterization to describe pyro‐convective dust emission together with its influencing factors sufficiently to enable a proper investigation of its atmospheric impacts. Key Points: Aerodynamic preconditions to favor dust emission through saltation and direct aerodynamic entrainment exist in fire vicinityStrength of relative contribution of both dust emission processes can vary significantly depending on wind, fire and soil‐surface conditionsAccurate estimation of global importance of fire‐related dust emissions requires development of an adjusted parameterization approach [ABSTRACT FROM AUTHOR]

Motor activity in healthy young humans displays intrinsic fluctuations that are scale-invariant over a wide range of time scales (from minutes to hours). Human postmortem and animal lesion studies showed that the intact function of the suprachiasmatic nucleus (SCN) is required to maintain such scale-invariant patterns. We therefore hypothesized that scale invariance is degraded in patients treated for suprasellar tumors that compress the SCN. To test the hypothesis, we investigated 68 patients with nonfunctioning pituitary macroadenoma and 22 patients with craniopharyngioma, as well as 72 age-matched healthy controls (age range 21.0-70.6 years). Spontaneous wrist locomotor activity was measured for 7 days with actigraphy, and detrended fluctuation analysis was applied to assess correlations over a range of time scales from minutes to 24 h. For all the subjects, complex scale-invariant correlations were only present for time scales smaller than 1.5 h, and became more random at time scales 1.5-10 h. Patients with suprasellar tumors showed a larger decrease in correlations at 1.5-10 h as compared to healthy controls. Within healthy subject, gender and age >33 year were associated with attenuated scale invariance. Conversely, activity patterns at time scales between 10 and 24 h were significantly more regular than all other time scales, and this was mostly associated with age. In conclusion, scale invariance is degraded in healthy subjects at the ages of >33 year as characterized by attenuation of correlations at time scales 1.5-10 h. In addition, scale invariance was more degraded in patients with suprasellar tumors as compared to healthy subjects. [ABSTRACT FROM AUTHOR]

Co-Firing biomass in the form of wood dust or sawdust with natural gas is a new concept, which was performed in a specialized burner from the Riga Technical University. In order to test the burner, primary experimental test runs were performed to get an overview of flue gas behaviour. The addition of sawdust increased CO values but O2 values remained very low in the flue gases. This was due to technical problems with the fuel. Co-Firing has the potential to reduce CO2 emissions of energy production and wood dust is an abundant by-product of forestry, therefore the potential has to be explored in future research.

Developing novel electrode materials is a substantial issue to improve the performance of lithium ion batteries. In the present study, single phase Ti–Sn alloys with different Sn contents of 1 to 10 at% were used to fabricate Ti–Sn–O nanotubes via a straight-forward anodic oxidation step in an ethylene glycol-based solution containing NH4F. Various characterization tools such as SEM, EDXS, TEM, XPS and Raman spectroscopy were used to characterize the grown nanotube films. Our results reveal the successful formation of mixed TiO2/SnO2 nanotubes in the applied voltage range of 10–40 V. The as-formed nanotubes are amorphous and their dimensions are precisely controlled by tuning the formation voltage which turns Ti–Sn–O nanotubes into highly attractive materials for various applications. As an example, the Ti–Sn–O nanotubes offer promising properties as anode materials in lithium ion batteries. The electrochemical performance of the grown nanotubes was evaluated against a Li/Li+ electrode at a current density of 504 μA cm−2. The results demonstrate that TiO2/SnO2 nanotubes prepared at 40 V on a TiSn1 alloy substrate display an average 1.4 fold increase in areal capacity with excellent cycling stability over more than 400 cycles compared to the pure TiO2 nanotubes fabricated and tested under identical conditions. This electrode was tested at current densities of 50, 100, 252, 504 and 1008 μA cm−2 exhibiting average capacities of 780, 660, 490, and 405 μA cm−2 (i.e. 410, 345, 305 and 212 mA h g−1), respectively. The remarkably improved electrochemical performance is attributed to enhanced lithium ion diffusion which originates from the presence of SnO2 nanotubes and the high surface area of the mixed oxide tubes. The TiO2/SnO2 electrodes retain their original tubular structure after electrochemical cycling with only slight changes in their morphology. [ABSTRACT FROM AUTHOR]

Different Cu-Co-O mixtures (CCO) with cation ratios from 5:1 to 1:5 were investigated as conversion type electrodes in half cells against lithium counter electrodes. To achieve a nearly homogeneous distribution of the elements on the nanometre scale, the self-combustion method was employed. The electrochemical redox behavior of the single oxides and CCO were characterized with cyclic voltammetry and galvanostatic cycling. These investigations showed different element specific electrochemical characteristics. Copper oxide was more stable with respect to cycling stability, while cobalt oxide had a higher specific capacity. The combination of both elements in ternary CCO leads to an improvement of the specific capacity and the cycling stability compared to the binary metal oxides of only copper and cobalt, respectively. This stabilization effect qualifies CCO as a promising model system to elucidate the underlying mechanisms in such composites with complex interactions between the different metals during conversion and in successive cycling. [ABSTRACT FROM AUTHOR]

Biomineralization by heavy metal resistant streptomycetes was tested to evaluate the potential influence on metal mobilities in soil. Thus, we designed an experiment adopting conditions from classical laboratory methods to natural conditions prevailing in metal-rich soils with media spiked with heavy metals, soil agar, and nutrient enriched or unamended soil incubated with the bacteria. As a result, all strains were able to form struvite minerals on tryptic soy broth (TSB) media supplemented with AICI2, MnCI2 and CuSO4, as well as on soil agar. Some strains additionally formed struvite on nutrient enriched contaminated and control soil, as well as on metal contaminated soil without addition of media components. In contrast, switzerite was exclusively formed on minimal media spiked with MnCI2 by four heavy metal resistant strains, and on nutrient enriched control soil by one strain. Hydrated nickel hydrogen phosphate was only crystallized on complex media supplemented with NiSO4 by most strains. Thus, mineralization is a dominant property of streptomycetes, with different processes likely to occur under laboratory conditions and sub-natural to natural conditions. This new understanding may be transferred to formation of minerals in rock and sediment evolution, to ore deposit formation, and also might have implications for our understanding of biological metal resistance mechanisms. We assume that biogeochemical cycles, nutrient storage and metal resistance might be affected by formation and re-solubilization of minerals like struvite in soil at microscale. [ABSTRACT FROM AUTHOR]

We develop a parameterization scheme of convective dust emission for regional and global atmospheric models. Convective dust emission occurs in the absence of saltation as large eddies intermittently produce strong shear stresses on the surface and entrain dust particles into the air. This dust emission mechanism has not been included in the traditional dust models. The scheme presented in this study is a new approach which takes account of the stochastic nature of convective dust emission. It consists of the statistical representations of soil particle size, inter-particle cohesion, and instantaneous surface shear stress. A method of determining the probability density function of the latter quantity is proposed. Dust emission is then estimated from the overlap of the probability density functions of the aerodynamic lifting and inter-particle cohesive forces. The new scheme is implemented into the WRF/Chem model and applied to dust modeling in the Taklimakan Desert. A comparison with lidar data shows that the model can reproduce the main features of the dust patterns and their diurnal variations. For the case studied, convective dust emission is typically several µgm-2s-1 and at times up to 50 µg m-2s-1. [ABSTRACT FROM AUTHOR]

Methane is an important end product of degradation of organic matter in anoxic lake sediments. Methane is mainly produced by either reduction of CO2 or cleavage of acetate involving different methanogenic archaea. The contribution of the different methanogenic paths and of the diverse bacteria and archaea involved in CH4 production exhibits a large variability that is not well understood. Lakes in tropical areas, e.g. in Brazil, are wetlands with high potential impact on the global CH4 budget. However, they have hardly been studied with respect to methanogenesis. Therefore, we used samples from 16 different lake sediments in the Pantanal and Amazon region of Brazil to measure production of CH4, CO2, analyze the content of 13C in the products and in intermediately formed acetate, determine the abundance of bacterial and archaeal microorgansisms and their community composition and diversity by targeting the genes of bacterial and archaeal ribosomal RNA and of methyl coenzyme M reductase, the key enzyme of methanogenic archaea. These experiments were done in the presence and absence of methyl fluoride, an inhibitor of acetoclastic methanogenesis. While production rates of CH4 and CO2 were correlated to the content of organic matter and the abundance of archaea in the sediment, values of 13C in acetate, CO2, and CH4 were related to the 13C content of organic matter and to the path of CH4 production with its intrinsic carbon isotope fractionation. Isotope fractionation was small (average 10%o) for conversion of Corg to acetate-methyl, which was hardly further fractionated during CH4 production. However, fractionation was strong for CO2 conversion to CH4 (average 75‰) which generally accounted for >50% of total CH4 production. Canonical correspondence analysis did not reveal an effect of microbial community composition, despite the fact that it exhibited a pronounced variability among the different sediments. [ABSTRACT FROM AUTHOR]

Methane is an important end product of degradation of organic matter in anoxic lake sediments. Methane is mainly produced by either reduction of CO2 or cleavage of acetate involving different methanogenic archaea. The contribution of the different methanogenic paths and of the diverse bacteria and archaea involved in CH4 production exhibits a large variability that is not well understood. Lakes in tropical areas, e.g. in Brazil, are wetlands with high potential impact on the global CH4 budget. However, they have hardly been studied with respect to methanogenesis. Therefore, we used samples from 16 different lake sediments in the Pantanal and Amazon region of Brazil to measure production of CH4, CO2, analyze the content of 13C in the products and in intermediately formed acetate, determine the abundance of bacterial and archaeal miroorgansisms and their community composition and diversity by targeting the genes of bacterial and archaeal ribosomal RNA and of methyl coenzyme M reductase, the key enzyme of methanogenic archaea. These experiments were done in the presence and absence of methyl fluoride, an inhibitor of acetoclastic methanogenesis. While production rates of CH4 and CO2 were correlated to the content of organic matter and the abundance of archaea in the sediment, values of 13C in acetate and CH4 were related to the 13C content of organic matter and to the path of CH4 production with its intrinsic carbon isotope fractionation. Isotope fractionation was small (average 10%) for conversion of Corg to acetateethyl, which was hardly further fractionated during CH4 production. However, fractionation was strong for CO2 conversion to CH4 (average 75%), which generally accounted for >50% of total CH4 production. Canonical correspondence analysis did not reveal an effect of microbial community composition, despite the fact that it exhibited a pronounced variability among the different sediments. [ABSTRACT FROM AUTHOR]

Flood risk communication with the general public and the population at risk is getting increasingly important for flood risk management, especially as a precautionary measure. This is also underlined by the EU Flood Directive. The flood related authorities therefore have to develop adjusted information tools which meet the demands of different user groups. This article presents the formative evaluation of flood hazard maps and web mapping services according to the specific requirements and needs of the general public using the dynamic-transactional approach as a theoretical framework. The evaluation was done by a mixture of different methods; an analysis of existing tools, a creative workshop with experts and laymen and an online survey. The currently existing flood hazard maps or web mapping services or web GIS still lack a good balance between simplicity and complexity with adequate readability and usability for the public. Well designed and associative maps (e.g. using blue colours for water depths) which can be compared with past local flood events and which can create empathy in viewers, can help to raise awareness, to heighten the activity and knowledge level or can lead to further information seeking. Concerning web mapping services, a linkage between general flood information like flood extents of different scenarios and corresponding water depths and real time information like gauge levels is an important demand by users. Gauge levels of these scenarios are easier to understand than the scientifically correct return periods or annualities. The recently developed Bavarian web mapping service tries to integrate these requirements. [ABSTRACT FROM AUTHOR]

This study explores the applicability of DNA analyses for the characterization of primary biogenic aerosol (PBA) particles in the atmosphere. Samples of fine particulate matter (PM2.5) and total suspended particulates (TSP) have been collected on different types of filter materials at urban, rural, and high-alpine locations along an altitude transect in the south of Germany (Munich, Hohenpeissenberg, Mt. Zugspitze). From filter segments loaded with about one milligram of air particulate matter, DNA could be extracted and DNA sequences could be determined for bacteria, fungi, plants and animals. Sequence analyses were used to determine the identity of biological organisms, and terminal restriction fragment length polymorphism analyses (T-RFLP) were applied to estimate diversities and relative abundances of bacteria. Investigations of blank and background samples showed that filter materials have to be decontaminated prior to use, and that the sampling and handling procedures have to be carefully controlled to avoid artifacts in the analyses. Mass fractions of DNA in PM2.5 were found to be around 0.05% in urban, rural, and high-alpine aerosols. The average concentration of DNA determined for urban air was on the order of ∼7 ngm-3, indicating that human adults may inhale about one microgram of DNA per day (corresponding to ∼108 haploid bacterial genomes or ∼105 haploid human genomes, respectively). Most of the bacterial sequences found in PM2.5 were from Proteobacteria (42) and some from Actinobacteria (10) and Firmicutes (1). The fungal sequences were characteristic for Ascomycota (3) and Basidiomycota (1), which are known to actively discharge spores into the atmosphere. The plant sequences could be attributed to green plants (2) and moss spores (2), while animal DNA was found only for one unicellular eukaryote (protist). Over 80% of the 53 bacterial sequences could be matched to one of the 19 T-RF peaks found in the PM2.5 samples, but only 40% of the T-RF peaks did correspond to one of the detected bacterial sequences. The results demonstrate that the T-RFLP analysis covered more of the bacterial diversity than the sequence analysis. Shannon-Weaver indices calculated from both sequence and T-RFLP data indicate that the bacterial diversity in the rural samples was higher than in the urban and alpine samples. Two of the bacterial sequences (Gammaproteobacteria) and five of the T-RF peaks were found at all sampling locations. [ABSTRACT FROM AUTHOR]

This study explores the applicability of molecular methods for the characterization of primary biogenic aerosol (PBA) particles in the atmosphere. Samples of fine particulate matter (PM2.5) and total suspended particulates (TSP) have been collected on different types of filter materials at urban, rural, and high-alpine locations along an altitude transect in the south of Germany (Munich, Hohenpeissenberg, Mt. Zugspitze). From filter aliquots loaded with about one milligram of air particulate matter, DNA could be extracted and DNA sequences could be determined for bacteria, fungi, plants and animals. Sequence analyses were used to determine the identity of biological organisms, and terminal restriction length polymorphism analyses (T-RFLP) were applied to estimate diversities and relative abundances of bacteria. Investigations of blank and background samples showed that filter materials have to be decontaminated prior to use, and that the sampling and handling procedures have to be carefully controlled to avoid artifacts in the analyses. Mass fractions of DNA in PM2.5 were found to be around 0.05% in urban, rural, and high alpine aerosols. The average concentration of DNA determined for urban air was on the order of ∼7 ng m-3, indicating that human adults may inhale about one microgram of DNA per day (corresponding to ∼105 haploid human genomes). Most of the bacterial sequences found in PM2.5 were from Proteobacteria (42) and some from Actinobacteria (10) and Firmicutes (1). The fungal sequences were characteristic for Ascomycota (3) and Basidiomycetes (1), which are known to actively discharge spores into the atmosphere. The plant sequences could be attributed to green plants (2) and moss spores (2), while animal DNA was found only for one unicellular eukaryote (protist). Over 80% of the 53 bacterial sequences could be matched with about 40% of the 19 T-RF peaks (58 to 494 base pair length) found in the investigated PM2.5 samples. The results demonstrate that the T-RFLP analysis covered more of the bacterial diversity than the sequence analysis. Shannon-Weaver indices calculated from both sequence and T-RFLP data indicate that the bacterial diversity in the rural samples was higher than in the urban and alpine samples. Two of the bacterial sequences (Gammaproteobacteria) and five of the T-RF peaks were found at all sampling locations. [ABSTRACT FROM AUTHOR]

Addition of rice straw, which is a common practice in rice agriculture, generally results in enhanced production and emission of the greenhouse gas methane (CH4). However, it is unclear whether straw addition affects only the activity or also the composition of the methanogenic microbial community. It is also unclear to what extent methanogenic archaea would be able to proliferate in the soil. Anoxic slurries of Italian rice-field soil produced CH4 after a lag, during which ferric iron and sulfate were reduced. Addition of rice straw slightly decreased this lag and greatly enhanced the subsequent production of CH4. At the same time, addition of rice straw enhanced the intermediate production of H2 and acetate that served as the methanogenic substrates. Compared with the unamended control, the addition of rice straw resulted in an increased concentration of phospholipid fatty acids in the soil. Quantitative ‘real-time’ PCR targeting the 16S rRNA gene also showed increased copy numbers of both Bacteria and Archaea in the straw-amended soil at the end of the experiment. The composition of the archaeal community was followed over time by terminal restriction length polymorphism (T-RFLP) analysis of the archaeal 16S rRNA genes extracted from straw-amended soil and the control. Rice Cluster-I (RC-I) methanogens and Methanosarcinaceae were the most abundant methanogenic populations, followed by Methanobacteriales, Methanomicrobiales and Methanosaetaceae. Addition of rice straw resulted in a relative increase of Methanosarcinaceae and Methanobacteriales and a relative decrease of RC-I methanogens and Methanomicrobiales. Our results revealed a dynamic methanogenic community in anoxic rice-field soil and showed that addition of organic matter selectively enhanced the growth of particular methanogenic populations, which were apparently better adapted to the presence of straw than the others. The extent of archaeal growth was consistent with that expected theoretically from the ambient Gibbs free energies of hydrogenotrophic and acetoclastic methanogenesis. [ABSTRACT FROM AUTHOR]