582 research outputs found

    Poster Abstract: A Channel Quality Metric for Interference-Aware Wireless Sensor Networks

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    Wirelesssensornetworkssharethespectrumwithotherwireless technologies. Hence, in order to minimize the effects of externalinterferencetheymustcarefullychoosethechannels for packet transmissions and reception. The identification of the best channels is, however, non-trivial. In this poster we present and evaluate a new channel quality metric that is based on the availability of channels over time rather than on the average energy in channels. Categories and Subject Descriptor

    Targeted Ablation of Oligodendrocytes Triggers Axonal Damage

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    Glial dysfunction has been implicated in a number of neurodegenerative diseases. In this study we investigated the consequences of glial and oligodendrocyte ablation on neuronal integrity and survival in Drosophila and adult mice, respectively. Targeted genetic ablation of glia was achieved in the adult Drosophila nervous system using the GAL80-GAL4 system. In mice, oligodendrocytes were depleted by the injection of diphtheria toxin in MOGi-Cre/iDTR double transgenic animals. Acute depletion of oligodendrocytes induced axonal injury, but did not cause neuronal cell death in mice. Ablation of glia in adult flies triggered neuronal apoptosis and resulted in a marked reduction in motor performance and lifespan. Our study shows that the targeted depletion of glia triggers secondary neurotoxicity and underscores the central contribution of glia to neuronal homeostasis. The models used in this study provide valuable systems for the investigation of therapeutic strategies to prevent axonal or neuronal damage

    Community engagement and data quality: best practices and lessons learned from a citizen science project on birdsong

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    Citizen Science (CS) is a research approach that has become popular in recent years and offers innovative potential for dialect research in ornithology. As the scepticism about CS data is still widespread, we analysed the development of a 3-year CS project based on the song of the Common Nightingale (Luscinia megarhynchos) to share best practices and lessons learned. We focused on the data scope, individual engagement, spatial distribution and species misidentifications from recordings generated before (2018, 2019) and during the COVID-19 outbreak (2020) with a smartphone using the ‘Naturblick’ app. The number of nightingale song recordings and individual engagement increased steadily and peaked in the season during the pandemic. 13,991 nightingale song recordings were generated by anonymous (64%) and non-anonymous participants (36%). As the project developed, the spatial distribution of recordings expanded (from Berlin based to nationwide). The rates of species misidentifications were low, decreased in the course of the project (10–1%) and were mainly affected by vocal similarities with other bird species. This study further showed that community engagement and data quality were not directly affected by dissemination activities, but that the former was influenced by external factors and the latter benefited from the app. We conclude that CS projects using smartphone apps with an integrated pattern recognition algorithm are well suited to support bioacoustic research in ornithology. Based on our findings, we recommend setting up CS projects over the long term to build an engaged community which generates high data quality for robust scientific conclusions.Gesellschaftliches Engagement und Datenqualität: Bewährte Praktiken und Erfahrungen aus einem bürgerwissenschaftlichen Projekt zum Vogelgesang Citizen Science (CS) ist eine Forschungsmethode, die in den letzten Jahren an Bedeutung gewonnen hat und innovatives Potenzial für die Dialektforschung in der Ornithologie bietet. Da die Vorbehalte gegenüber CS-Daten immer noch weit verbreitet sind, haben wir die Entwicklung eines dreijährigen CS-Projekts zum Gesang der Nachtigall (Luscinia megarhynchos) analysiert, um bewährte Praktiken und gewonnene Erfahrungen darzustellen. Wir fokussierten uns auf den Datenumfang, das individuelle Engagement von Teilnehmenden, die räumliche Verteilung und die Fehlbestimmungen von Arten aus Aufnahmen, die vor (2018, 2019) und während des COVID-19-Ausbruchs (2020) mit einem Smartphone unter Verwendung der "Naturblick" App erstellt wurden. Die Anzahl der Aufnahmen von Nachtigallgesängen und das individuelle Engagement stiegen stetig an und erreichten ihren Höhepunkt in der Saison während der Pandemie. 13.991 Aufnahmen von Nachtigallgesängen wurden von anonymen (64%) und nicht-anonymen Teilnehmenden (36%) erstellt. Im Laufe des Projekts weitete sich die räumliche Verteilung der Aufnahmen aus (von Berlin auf bundesweit). Die Rate der Fehlbestimmungen war gering, ging im Laufe des Projekts zurück (von 10% auf 1%) und wurde hauptsächlich von gesanglichen Ähnlichkeiten mit anderen Vogelarten beeinflusst. Unsere Studie zeigte außerdem, dass das gesellschaftliche Engagement und die Datenqualität nicht direkt von den durchgeführten Disseminationsaktivitäten beeinflusst wurden, sondern dass erstere von externen Faktoren abhingen und letztere von der App profitierte. Wir schließen daraus, dass CS-Projekte, die Smartphone-Apps mit einem integrierten Mustererkennungsalgorithmus verwenden, gut geeignet sind, um die bioakustische Forschung in der Ornithologie zu unterstützen. Auf der Grundlage unserer Ergebnisse empfehlen wir, CS-Projekte langfristig zu etablieren, um eine aktive Teilnehmergemeinschaft (Community) aufzubauen, die qualitativ hochwertige Daten für fundierte wissenschaftliche Schlussfolgerungen generiert

    Roman water management impacted the hydrological functioning of wetlands during drought periods

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    During the Roman domain of the Iberian Peninsula (from 201 BCE to 460 CE) water management infrastructures were built to satisfy high water demand. However, whether the Roman activities affected the hydrological balance of Iberian wetlands remains unclear. Here, we investigate the paleo-hydrology of Lake Zóñar (southern Iberia) by using the stable isotopes (16O, 17O, 18O, 1H and 2H) of its gypsum (CaSO4·2H2O) sediments and reconstruct the isotopic composition of the lake water during Roman times. A period of recurrent lake low stand occurred between 2120 and 1890 cal. yr BP (ca. 170 BCE to 60 CE), coinciding with a relatively dry climate stage recorded by most regional paleoclimate archives. The stable isotopes and hydrochemistry of the lake water during gypsum precipitation are consistent with a shallow saline lake that evaporated under relative humidity ~ 10% lower than the present annual mean and at least 20% less rainfall amount. Our analytical and archeological findings support lake level lowering during the Roman period was probably caused by combined arid climate conditions and diversion of the inlets feeding the lake. Spring capturing was likely necessary to satisfy the high water demand of nearby Roman settlements, in the framework of a period of persistent droughts

    5-teilige Sonderausgabe des KOBV-Newsletters – 24. bis 30. Oktober 2016

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    An der internationalen Open-Access-Woche 2016 vom 24.-28. Oktober war der KOBV erstmalig mit einem Online „Publishing Event“ beteiligt. An fünf aufeinanderfolgenden Tagen erschien täglich eine Sonderausgabe des KOBV- Newsletters zu ausgewählten Open-Access-Themen. Die einzelnen Beiträge sind in dieser Sonderedition als Online-Reader zusammengestellt. Der aktuelle Diskussionsstand zum jeweiligen Thema wird von Expertinnen und Experten in kurzen Übersichtsartikeln vorgestellt und mit Praxistipps ergänzt. Zielgruppe sind vor allem Bibliothekare und Bibliothekarinnen, die sich einen schnellen Überblick zu Open Access verschaffen wollen

    In vitro analysis of the effects on wound healing of high- and low-molecular weight chains of hyaluronan and their hybrid H-HA/L-HA complexes

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    Abstract Background: Recent studies have reported the roles of Hyaluronic acid (HA) chains of diverse length in wound repair, especially considering the simultaneous occurrence in vivo of both high- (H-HA) and low-molecular weight (L-HA) hyaluronan at an injury site. It has been shown that HA fragments (5 ≤ MW ≤ 20 kDa) usually trigger an inflammatory response that, on one hand, is the first signal in the activation of a repair mechanism but on the other, when it’s overexpressed, it may promote unwanted side effects. The present experimental research has aimed to investigate H-HA, L-HA and of a newly developed complex of the two (H-HA/L-HA) for stability (e.g. hyaluronidases digestion), for their ability to promote wound healing of human keratinocytes in vitro and for their effect on cellular biomarker expression trends. Results: Time-lapse video microscopy studies proved that the diverse HA was capable of restoring the monolayer integrity of HaCat. The H-HA/L-HA complex (0.1 and 1%w/v) proved faster in regeneration also in co-culture scratch test where wound closure was achieved in half the time of H-HA stimulated cells and 2.5-fold faster than the control. Gene expression was evaluated for transformation growth factor beta 1 (TGF-β1) proving that L-HA alone increased its expression at 4 h followed by restoration of similar trends for all the stimuli. Depending on the diverse stimulation (H-HA, L-HA or the complex), metalloproteinases (MMP-2, -9, -13) were also modulated differently. Furthermore, type I collagen expression and production were evaluated. Compared to the others, persistence of a significant higher expression level at 24 h for the H-HA/L-HA complex was found. Conclusions: The outcomes of this research showed that, both at high and low concentrations, hybrid complexes proved to perform better than HA alone thus suggesting their potential as medical devices in aesthetic and regenerative medicine. Keywords: Wound healing, Hyaluronan, MMPs, Hybrid complexe

    MOSAiC-ACA and AFLUX - Arctic airborne campaigns characterizing the exit area of MOSAiC

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    Two airborne field campaigns focusing on observations of Arctic mixed-phase clouds and boundary layer processes and their role with respect to Arctic amplification have been carried out in spring 2019 and late summer 2020 over the Fram Strait northwest of Svalbard. The latter campaign was closely connected to the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. Comprehensive data sets of the cloudy Arctic atmosphere have been collected by operating remote sensing instruments, insitu probes, instruments for the measurement of turbulent fluxes of energy and momentum, and dropsondes on board the AWI research aircraft Polar 5. In total, 24 flights with 111 flight hours have been performed over open ocean, the marginal sea ice zone, and sea ice. The data sets follow documented methods and quality assurance and are suited for studies on Arctic mixed-phase clouds and their transformation processes, for studies with a focus on Arctic boundary layer processes, and for satellite validation application

    Non-Standard Errors

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    In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty: Non-standard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for better reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants

    Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

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    Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

    Overview of the MOSAiC expedition - Atmosphere

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    With the Arctic rapidly changing, the needs to observe, understand, and model the changes are essential. To support these needs, an annual cycle of observations of atmospheric properties, processes, and interactions were made while drifting with the sea ice across the central Arctic during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from October 2019 to September 2020. An international team designed and implemented the comprehensive program to document and characterize all aspects of the Arctic atmospheric system in unprecedented detail, using a variety of approaches, and across multiple scales. These measurements were coordinated with other observational teams to explore cross-cutting and coupled interactions with the Arctic Ocean, sea ice, and ecosystem through a variety of physical and biogeochemical processes. This overview outlines the breadth and complexity of the atmospheric research program, which was organized into 4 subgroups: atmospheric state, clouds and precipitation, gases and aerosols, and energy budgets. Atmospheric variability over the annual cycle revealed important influences from a persistent large-scale winter circulation pattern, leading to some storms with pressure and winds that were outside the interquartile range of past conditions suggested by long-term reanalysis. Similarly, the MOSAiC location was warmer and wetter in summer than the reanalysis climatology, in part due to its close proximity to the sea ice edge. The comprehensiveness of the observational program for characterizing and analyzing atmospheric phenomena is demonstrated via a winter case study examining air mass transitions and a summer case study examining vertical atmospheric evolution. Overall, the MOSAiC atmospheric program successfully met its objectives and was the most comprehensive atmospheric measurement program to date conducted over the Arctic sea ice. The obtained data will support a broad range of coupled-system scientific research and provide an important foundation for advancing multiscale modeling capabilities in the Arctic
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