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- ItemA customizable microfluidic platform for medium-throughput modeling of neuromuscular circuits(Amsterdam [u.a.] : Elsevier Science, 2019) Bellmann, Jessica; Goswami, Ruchi Y.; Girardo, Salvatore; Rein, Nelly; Hosseinzadeh, Zohreh; Hicks, Michael R.; Busskamp, Volker; Pyle, April D.; Werner, Carsten; Sterneckert, JaredNeuromuscular circuits (NMCs) are vital for voluntary movement, and effective models of NMCs are needed to understand the pathogenesis of, as well as to identify effective treatments for, multiple diseases, including Duchenne's muscular dystrophy and amyotrophic lateral sclerosis. Microfluidics are ideal for recapitulating the central and peripheral compartments of NMCs, but myotubes often detach before functional NMCs are formed. In addition, microfluidic systems are often limited to a single experimental unit, which significantly limits their application in disease modeling and drug discovery. Here, we developed a microfluidic platform (MFP) containing over 100 experimental units, making it suitable for medium-throughput applications. To overcome detachment, we incorporated a reactive polymer surface allowing customization of the environment to culture different cell types. Using this approach, we identified conditions that enable long-term co-culture of human motor neurons and myotubes differentiated from human induced pluripotent stem cells inside our MFP. Optogenetics demonstrated the formation of functional NMCs. Furthermore, we developed a novel application of the rabies tracing assay to efficiently identify NMCs in our MFP. Therefore, our MFP enables large-scale generation and quantification of functional NMCs for disease modeling and pharmacological drug targeting. © 2019 The Authors
- ItemA survey on Bluetooth multi-hop networks(Amsterdam [u.a.] : Elsevier Science, 2019) Todtenberg, Nicole; Kraemer, RolfBluetooth was firstly announced in 1998. Originally designed as cable replacement connecting devices in a point-to-point fashion its high penetration arouses interest in its ad-hoc networking potential. This ad-hoc networking potential of Bluetooth is advertised for years - but until recently no actual products were available and less than a handful of real Bluetooth multi-hop network deployments were reported. The turnaround was triggered by the release of the Bluetooth Low Energy Mesh Profile which is unquestionable a great achievement but not well suited for all use cases of multi-hop networks. This paper surveys the tremendous work done on Bluetooth multi-hop networks during the last 20 years. All aspects are discussed with demands for a real world Bluetooth multi-hop operation in mind. Relationships and side effects of different topics for a real world implementation are explained. This unique focus distinguishes this survey from existing ones. Furthermore, to the best of the authors’ knowledge this is the first survey consolidating the work on Bluetooth multi-hop networks for classic Bluetooth technology as well as for Bluetooth Low Energy. Another individual characteristic of this survey is a synopsis of real world Bluetooth multi-hop network deployment efforts. In fact, there are only four reports of a successful establishment of a Bluetooth multi-hop network with more than 30 nodes and only one of them was integrated in a real world application - namely a photovoltaic power plant. © 2019 The Authors
- ItemOn the geometric stability of an inorganic nanowire and an organic ligand shell(Amsterdam [u.a.] : Elsevier Science, 2019) Bettscheider, Simon; Kraus, Tobias; Fleck, NormanA.The break-up of a nanowire with an organic ligand shell into discrete droplets is analysed in terms of the Rayleigh-Plateau instability. Explicit account is taken of the effect of the organic ligand shell upon the energetics and kinetics of surface diffusion in the wire. Both an initial perturbation analysis and a full numerical analysis of the evolution in wire morphology are conducted, and the governing non-dimensional groups are identified. The perturbation analysis is remarkably accurate in obtaining the main features of the instability, including the pinch-off time and the resulting diameter of the droplets. It is conjectured that the surface energy of the wire and surrounding organic shell depends upon both the mean and deviatoric invariants of the curvature tensor. Such a behaviour allows for the possibility of a stable nanowire such that the Rayleigh-Plateau instability is not energetically favourable. A stability map illustrates this. Maps are also constructed for the final droplet size and pinch-off time as a function of two non-dimensional groups that characterise the energetics and kinetics of diffusion in the presence of the organic shell. These maps can guide future experimental activity on the stabilisation of nanowires by organic ligand shells. © 2018 The Authors
- ItemA new method to measure real-world respiratory tract deposition of inhaled ambient black carbon(Amsterdam [u.a.] : Elsevier Science, 2019) Madueño, Leizel; Kecorius, Simonas; Löndahl, Jakob; Müller, Thomas; Pfeifer, Sascha; Haudek, Andrea; Mardoñez, Valeria; Wiedensohler, AlfredIn this study, we present the development of a mobile system to measure real-world total respiratory tract deposition of inhaled ambient black carbon (BC). Such information can be used to supplement the existing knowledge on air pollution-related health effects, especially in the regions where the use of standard methods and intricate instrumentation is limited. The study is divided in two parts. Firstly, we present the design of portable system and methodology to evaluate the exhaled air BC content. We demonstrate that under real-world conditions, the proposed system exhibit negligible particle losses, and can additionally be used to determine the minute ventilation. Secondly, exemplary experimental data from the system is presented. A feasibility study was conducted in the city of La Paz, Bolivia. In a pilot experiment, we found that the cumulative total respiratory tract deposition dose over 1-h commuting trip would result in approximately 2.6 μg of BC. This is up to 5 times lower than the values obtained from conjectural approach (e.g. using physical parameters from previously reported worksheets). Measured total respiratory tract deposited BC fraction varied from 39% to 48% during walking and commuting inside a micro-bus, respectively. To the best of our knowledge, no studies focusing on experimental determination of real-world deposition dose of BC have been performed in developing regions. This can be especially important because the BC mass concentration is significant and determines a large fraction of particle mass concentration. In this work, we propose a potential method, recommendations, as well as the limitations in establishing an easy and relatively cheap way to estimate the respiratory tract deposition of BC. In this study we present a novel method to measure real-world respiratory tract deposition dose of Black Carbon. Results from a pilot study in La Paz, Bolivia, are presented. © 2019 The Authors
- ItemComparison of ammonia emissions related to nitrogen use efficiency of livestock production in Europe(Amsterdam [u.a.] : Elsevier Science, 2019) Groenestein, C.M.; Hutchings, N.J.; Haenel, H.D.; Amon, B.; Menzi, H.; Mikkelsen, M.H.; Misselbrook, T.H.; van Bruggen, C.; Kupper, T.; Webb, J.The increasing global demand for food and the environmental effects of reactive nitrogen losses in the food production chain, increase the need for efficient use of nitrogen (N). Of N harvested in agricultural plant products, 80% is used to feed livestock. Because the largest atmospheric loss of reactive nitrogen from livestock production systems is ammonia (NH3), the focus of this paper is on N lost as NH3 during the production of animal protein. The focus of this paper is to understand the key factors explaining differences in Nitrogen Use Efficiency (NUE) of animal production among various European countries. Therefore we developed a conceptual framework to describe the NUE defined as the amount of animal-protein N per N in feed and NH3–N losses in the production of milk, beef, pork, chicken meat and eggs in The Netherlands, Switzerland, United Kingdom, Germany, Austria and Denmark. The framework describes how manure management and animal-related parameters (feed, metabolism) relate to NH3 emissions and NUE. The results showed that the animal product with the lowest NUE had the largest NH3 emissions and vice versa, which agrees with the reciprocal relationship between NUE and NH3 within the conceptual framework. Across animal products for the countries considered, about 20% of the N in feed is lost as NH3. The significant smallest proportion (12%) of NH3–N per unit of Nfeed is from chicken production. The proportions for other products are 17%, 19%, 20% and 22% for milk, pork, eggs and beef respectively. These differences were not significantly different due to the differences among countries. For all countries, NUE was lowest for beef and highest for chicken. The production of 1 kg N in beef required about 5 kg N in feed, of which 1 kg N was lost as NH3–N. For the production of 1 kg N in chicken meat, 2 kg N in feed was required and 0.2 kg was lost as NH3. The production of 1 kg N in milk required 4 kg N in feed with 0.6 kg NH3–N loss, the same as pork and eggs, but those needed 3 and 3.5 kg N in feed per kg N in product respectively. Except for beef, the differences among these European countries were mainly caused by differences in manure management practices and their emission factors, rather than by animal-related factors including feed and digestibility influencing the excreted amount of ammoniacal N (TAN). For beef, both aspects caused important differences. Based on the results, we encourage the expression of N losses as per N in feed or per N in product, in addition to per animal place, when comparing production efficiency and NUE. We consider that disaggregating emission factors into a diet/animal effect and a manure management effect would improve the basis for comparing national NH3 emission inventories. © 2018 The Authors
- ItemProducing Policy-relevant Science by Enhancing Robustness and Model Integration for the Assessment of Global Environmental Change(Amsterdam [u.a.] : Elsevier Science, 2019) Warren, R.F.; Edwards, N.R.; Babonneau, F.; Bacon, P.M.; Dietrich, J.P.; Ford, R.W.; Garthwaite, P.; Gerten, D.; Goswami, S.; Haurie, A.; Hiscock, K.; Holden, P.B.; Hyde, M.R.; Joshi, S.R.; Kanudia, A.; Labriet, M.; Leimbach, M.; Oyebamiji, O.K.; Osborn, T.; Pizzileo, B.; Popp, A.; Price, J.; Riley, G.D.; Schaphoff, S.; Slavin, P.; Vielle, M.; Wallace, C.We use the flexible model coupling technology known as the bespoke framework generator to link established existing modules representing dynamics in the global economy (GEMINI_E3), the energy system (TIAM-WORLD), the global and regional climate system (MAGICC6, PLASIM-ENTS and ClimGEN), the agricultural system, the hydrological system and ecosystems (LPJmL), together in a single integrated assessment modelling (IAM) framework, building on the pre-existing framework of the Community Integrated Assessment System. Next, we demonstrate the application of the framework to produce policy-relevant scientific information. We use it to show that when using carbon price mechanisms to induce a transition from a high-carbon to a low-carbon economy, prices can be minimised if policy action is taken early, if burden sharing regimes are used, and if agriculture is intensified. Some of the coupled models have been made available for use at a secure and user-friendly web portal. © 2018 The Authors
- ItemA novel multidrug-resistant PVL-negative CC1-MRSA-IV clone emerging in Ireland and Germany likely originated in South-Eastern Europe(Amsterdam [u.a.] : Elsevier Science, 2019) Earls, Megan R.; Shore, Anna C.; Brennan, Gráinne I.; Simbeck, Alexandra; Schneider-Brachert, Wulf; Vremerǎ, Teodora; Dorneanu, Olivia S.; Slickers, Peter; Ehricht, Ralf; Monecke, Stefan; Coleman, David C.This study investigated the recent emergence of multidrug-resistant Panton-Valentine leukocidin (PVL)-negative CC1-MRSA-IV in Ireland and Germany. Ten CC1-MSSA and 139 CC1-MRSA isolates recovered in Ireland between 2004 and 2017 were investigated. These were compared to 21 German CC1-MRSA, 10 Romanian CC1-MSSA, five Romanian CC1-MRSA and two UAE CC1-MRSA, which were selected from an extensive global database, based on similar DNA microarray profiles to the Irish isolates. All isolates subsequently underwent whole-genome sequencing, core-genome single nucleotide polymorphism (cgSNP) analysis and enhanced SCCmec subtyping. Two PVL-negative clades (A and B1) were identified among four main clades. Clade A included 20 German isolates, 119 Irish isolates, and all Romanian MRSA and MSSA isolates, the latter of which differed from clade A MRSA by 47–130 cgSNPs. Eighty-six Irish clade A isolates formed a tight subclade (A1) exhibiting 0–49 pairwise cgSNPs, 80 of which harboured a 46 kb conjugative plasmid carrying both ileS2, encoding high-level mupirocin resistance, and qacA, encoding chlorhexidine resistance. The resistance genes aadE, aphA3 and sat were detected in all clade A MRSA and the majority (8/10) of clade A MSSA isolates. None of the clade A isolates harboured any enterotoxin genes other than seh, which is universally present in CC1. Clade B1 included the remaining German isolate, 17 Irish isolates and the two UAE isolates, all of which corresponded to the Western Australia MRSA-1 (WA MRSA-1) clone based on genotypic characteristics. MRSA within clades A and B1 differed by 188 cgSNPs and clade-specific SCCmec characteristics were identified, indicating independent acquisition of the SCCmec element. This study demonstrated the existence of a European PVL-negative CC1-MRSA-IV clone that is distinctly different from the well-defined PVL-negative CC1-MRSA-IV clone, WA MRSA-1. Furthermore, cgSNP analysis revealed that this newly defined clone may have originated in South-Eastern Europe, before spreading to both Ireland and Germany. © 2019 The Authors
- ItemInfrequent new particle formation over the remote boreal forest of Siberia(Amsterdam [u.a.] : Elsevier Science, 2018) Wiedensohler, A.; Ma, N.; Birmili, W.; Heintzenberg, J.; Ditas, F.; Andreae, M.O.; Panov, A.Aerosol particle number size distributions (PNSD) were investigated to verify, if extremely low-volatility organic vapors (ELVOC) from natural sources alone could induce new particle formation and growth events over the remote boreal forest region of Siberia, hundreds of kilometers away from significant anthropogenic sources. We re-evaluated observations determined at a height of 300 m of the remote observatory ZOTTO (Zotino Tall Tower Observatory, http://www.zottoproject.org). We found that new particle formation events occurred only on 11 days in a 3-year period, suggesting that homogeneous nucleation with a subsequent condensational growth could not be the major process, maintaining the particle number concentration in the planetary boundary layer of the remote boreal forest area of Siberia. © 2018 Elsevier Ltd
- ItemVariability of black carbon mass concentrations, sub-micrometer particle number concentrations and size distributions: results of the German Ultrafine Aerosol Network ranging from city street to High Alpine locations(Amsterdam [u.a.] : Elsevier Science, 2018) Sun, J.; Birmili, W.; Hermann, M.; Tuch, T.; Weinhold, K.; Spindler, G.; Schladitz, A.; Bastian, S.; Löschau, G.; Cyrys, J.; Gu, J.; Flentje, H.; Briel, B.; Asbac, C.; Kaminski, H.; Ries, L.; Sohme, R.; Gerwig, H.; Wirtz, K.; Meinhardt, F.; Schwerin, A.; Bath, O.; Ma, N.; Wiedensohler, A.This work reports the first statistical analysis of multi-annual data on tropospheric aerosols from the German Ultrafine Aerosol Network (GUAN). Compared to other networks worldwide, GUAN with 17 measurement locations has the most sites equipped with particle number size distribution (PNSD) and equivalent black carbon (eBC) instruments and the most site categories in Germany ranging from city street/roadside to High Alpine. As we know, the variations of eBC and particle number concentration (PNC) are influenced by several factors such as source, transformation, transport and deposition. The dominant controlling factor for different pollutant parameters might be varied, leading to the different spatio-temporal variations among the measured parameters. Currently, a study of spatio-temporal variations of PNSD and eBC considering the influences of both site categories and spatial scale is still missing. Based on the multi-site dataset of GUAN, the goal of this study is to investigate how pollutant parameters may interfere with spatial characteristics and site categories. © 2019 The Authors
- ItemDo new sea spray aerosol source functions improve the results of a regional aerosol model?(Amsterdam [u.a.] : Elsevier Science, 2018) Barthel, Stefan; Tegen, Ina; Wolke, RalfSea spray aerosol particle is a dominating part of the global aerosol mass load of natural origin. Thus, it strongly influences the atmospheric radiation balance and cloud properties especially over the oceans. Uncertainties of the estimated climate impacts by this aerosol type are partly caused by the uncertainties in the particle size dependent emission fluxes of sea spray aerosol particle. We present simulations with a regional aerosol transport model system in two domains, for three months and compared the model results to measurements at four stations using various sea spray aerosol particle source source functions. Despite these limitations we found the results using different source functions are within the range of most model uncertainties. Especially the model's ability to produce realistic wind speeds is crucial. Furthermore, the model results are more affected by a function correcting the emission flux for the effect of the sea surface temperature than by the use of different source functions. © 2018 The Authors