Differenzierte Bioaerosolmessungen: Größenfraktionierte und kontinuierliche Messung von Bioaerosolen in der Emission von Geflügelhaltungen

Es wurden erstmals die Größenverteilungen von Bioaerosolen, sowie deren tageszeitlicher Konzentrationsverlauf in der Emission von Anlagen zur Geflügelhaltung mittels standardisierter Verfahren bestimmt. Die Ergebnisse richten sich im Rahmen von Genehmigungsverfahren an Anlagenbetreiber, Gutachter und Behörden. Sie legen nahe, dass zukünftig sowohl die Partikelgrößenverteilung, als auch die tageszeitlichen Emissionsschwankungen bei der Ausbreitungsrechnung von Bioaerosolen berücksichtigt werden sollten. Bezüglich der verwendeten Emissionsfaktoren wird eine Halbierung des Konventionswertes für Legehennen und Putenmast aufgezeigt, bezüglich des Größenklassenspektrums für Anlagen der Geflügelhaltung eine Aufteilung von 15 % PM 2,5; 25 % PM 10; und 60 % TSP. Redaktionsschluss: 31.01.201

Datensatz: Differenzierte Bioaerosolmessungen

Datenmeldung nach dem EGovG. Der Datensatz kann auf Anfrage zur Verfügung gestellt werden. Eine Datennutzungsvereinbarung wird abgeschlossen. Datensatz zu differenzierte Bioaerosolmessung (Größenverteilung und Zeitreihe) in den Emission von Geflügelställen

Comparing and combining different climate mitigation measures in aviation

In the context of aviation’s significant contribution to anthropogenic climate change from CO2 and non-CO2 emissions, ambitious climate goals have been defined for the aviation industry that require an implementation of extensive measures from technical, regulatory and operational perspectives. While technical innovations including new aircraft designs and alternative fuels are expected to contribute significantly in the long run as they are associated with late entry-into-service, operational measures can benefit from their fast implementation with the current world fleet. Regulatory implementation enablers can further support the required changes to the air transport system. While the current state of research comprises a broad variety of studies on individual climate mitigation measures, a direct comparison and combination of the achieved results is typically not directly possible due to different reference cases, application scopes, and modelling assumptions as well as different maturities and expected realization times. However, a direct comparability is required to identify especially effective and efficient measures as well as to combine individual approaches in order to compare the resulting potentials towards the defined climate goals. This study aims to address the lack of comparability by developing an approach to compare and combine different climate mitigation measures. We consider different concepts addressing technical, operational as well as regulatory aspects. Based on the individual assessment of climate mitigation measures, we expand a previously developed generalization approach to scale individual results from measures-specific studies to a comparable scope considering varying traffic samples, assessment methods as well as temporal and spatial boundary conditions of the individual studies. Differences in maturities and possible entry-into-service times are also incorporated. Hence, different combinations of mitigation measures can be analysed regarding their climate mitigation potential in terms of temperature change as well as their operational applicability. Finally, possible combinations of the selected measures can be contrasted with defined climate goals

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Differenzierte Bioaerosolmessungen: Größenfraktionierte und kontinuierliche Messung von Bioaerosolen in der Emission von Geflügelhaltungen

Es wurden erstmals die Größenverteilungen von Bioaerosolen, sowie deren tageszeitlicher Konzentrationsverlauf in der Emission von Anlagen zur Geflügelhaltung mittels standardisierter Verfahren bestimmt. Die Ergebnisse richten sich im Rahmen von Genehmigungsverfahren an Anlagenbetreiber, Gutachter und Behörden. Sie legen nahe, dass zukünftig sowohl die Partikelgrößenverteilung, als auch die tageszeitlichen Emissionsschwankungen bei der Ausbreitungsrechnung von Bioaerosolen berücksichtigt werden sollten. Bezüglich der verwendeten Emissionsfaktoren wird eine Halbierung des Konventionswertes für Legehennen und Putenmast aufgezeigt, bezüglich des Größenklassenspektrums für Anlagen der Geflügelhaltung eine Aufteilung von 15 % PM 2,5; 25 % PM 10; und 60 % TSP

Differenzierte Bioaerosolmessungen: Größenfraktionierte und kontinuierliche Messung von Bioaerosolen in der Emission von Geflügelhaltungen

Es wurden erstmals die Größenverteilungen von Bioaerosolen, sowie deren tageszeitlicher Konzentrationsverlauf in der Emission von Anlagen zur Geflügelhaltung mittels standardisierter Verfahren bestimmt. Die Ergebnisse richten sich im Rahmen von Genehmigungsverfahren an Anlagenbetreiber, Gutachter und Behörden. Sie legen nahe, dass zukünftig sowohl die Partikelgrößenverteilung, als auch die tageszeitlichen Emissionsschwankungen bei der Ausbreitungsrechnung von Bioaerosolen berücksichtigt werden sollten. Bezüglich der verwendeten Emissionsfaktoren wird eine Halbierung des Konventionswertes für Legehennen und Putenmast aufgezeigt, bezüglich des Größenklassenspektrums für Anlagen der Geflügelhaltung eine Aufteilung von 15 % PM 2,5; 25 % PM 10; und 60 % TSP. Redaktionsschluss: 31.01.201

Comparison of LiDAR and digital aerial photogrammetry for characterizing canopy openings in the Boreal Forest of Northern Alberta

Forest canopy openings are a key element of forest structure, influencing a host of ecological dynamics. Light detection and ranging (LiDAR) is the de-facto standard for measuring three-dimensional forest structure, but digital aerial photogrammetry (DAP) has emerged as a viable and economical alternative. We compared the performance of LiDAR and DAP data for characterizing canopy openings and no-openings across a 1-km2 expanse of boreal forest in northern Alberta, Canada. Structural openings in canopy cover were delineated using three canopy height model (CHM) alternatives, from (i) LiDAR, (ii) DAP, and (iii) a LiDAR/DAP hybrid. From a point-based detectability perspective, the LiDAR CHM produced the best results (87% overall accuracy), followed by the hybrid and DAP models (47% and 46%, respectively). The hybrid and DAP CHMs experienced large errors of omission (9–53%), particularly with small openings up to 20m2, which are an important element of boreal forest structure. By missing these, DAP and hybrid datasets substantially under-reported the total area of openings across our site (152,470 m2 and 159,848 m2, respectively) compared to LiDAR (245,920 m2). Our results illustrate DAP’s sensitivity to occlusions, mismatched tie points, and other optical challenges inherent to using structure-from-motion workflows in complex forest scenes. These under-documented constraints currently limit the technology’s capacity to fully characterize canopy structure. For now, we recommend that operational use of DAP in forests be limited to mapping large canopy openings, and area-based attributes that are well-documented in the literature

Bacillus thuringiensis CbpA is a collagen binding cell surface protein under c-di-GMP control

Cyclic diguanylate (c-di-GMP) signalling affects several cellular processes in Bacillus cereus group bacteria including biofilm formation and motility, and CdgF was previously identified as a diguanylate cyclase promoting biofilm formation in B. thuringiensis. C-di-GMP can exert its function as a second messenger via riboswitch binding, and a functional c-di-GMP-responsive riboswitch has been found upstream of cbpA in various B. cereus group strains. Protein signature recognition predicted CbpA to be a cell wall-anchored surface protein with a fibrinogen or collagen binding domain. The aim of this study was to identify the binding ligand of CbpA and the function of CbpA in cellular processes that are part of the B. cereus group c-di-GMP regulatory network. By global gene expression profiling cbpA was found to be down-regulated in a cdgF deletion mutant, and cbpA exhibited maximum expression in early exponential growth. Contrary to the wild type, a ΔcbpA deletion mutant showed no binding to collagen in a cell adhesion assay, while a CbpA overexpression strain exhibited slightly increased collagen binding compared to the control. For both fibrinogen and fibronectin there was however no change in binding activity compared to controls, and CbpA did not appear to contribute to binding to abiotic surfaces (polystyrene, glass, steel). Also, the CbpA overexpression strain appeared to be less motile and showed a decrease in biofilm formation compared to the control. This study provides the first experimental proof that the binding ligand of the c-di-GMP regulated adhesin CbpA is collagen

Comparison of LiDAR and Digital Aerial Photogrammetry for Characterizing Canopy Openings in the Boreal Forest of Northern Alberta

Forest canopy openings are a key element of forest structure, influencing a host of ecological dynamics. Light detection and ranging (LiDAR) is the de-facto standard for measuring three-dimensional forest structure, but digital aerial photogrammetry (DAP) has emerged as a viable and economical alternative. We compared the performance of LiDAR and DAP data for characterizing canopy openings and no-openings across a 1-km2 expanse of boreal forest in northern Alberta, Canada. Structural openings in canopy cover were delineated using three canopy height model (CHM) alternatives, from (i) LiDAR, (ii) DAP, and (iii) a LiDAR/DAP hybrid. From a point-based detectability perspective, the LiDAR CHM produced the best results (87% overall accuracy), followed by the hybrid and DAP models (47% and 46%, respectively). The hybrid and DAP CHMs experienced large errors of omission (9–53%), particularly with small openings up to 20m2, which are an important element of boreal forest structure. By missing these, DAP and hybrid datasets substantially under-reported the total area of openings across our site (152,470 m2 and 159,848 m2, respectively) compared to LiDAR (245,920 m2). Our results illustrate DAP’s sensitivity to occlusions, mismatched tie points, and other optical challenges inherent to using structure-from-motion workflows in complex forest scenes. These under-documented constraints currently limit the technology’s capacity to fully characterize canopy structure. For now, we recommend that operational use of DAP in forests be limited to mapping large canopy openings, and area-based attributes that are well-documented in the literature.</jats:p