447 research outputs found

    Differentiation processes in treecreepers (Aves: Certhia): phylogeny, vocalisations, morphometrics

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    Kurzfassung der Dissertation an der Johannes Gutenberg-UniversitĂ€t Mainz, Fachbereich Biologie, Institut fĂŒr Zoologie (2007), betreut durch Prof. Dr. Jochen Martens

    Bird sounds as taxonomic characters

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    Die mit der Fortpflanzung verbundenen LautĂ€ußerungen der Vögel sind meist artspezifisch, so dass sie als taxonomische Merkmale verwendet werden können. Besondere Relevanz kommt ihnen dabei zu, wenn bei Vögeln, die Gesang erlernen können, Artbildungsprozesse beschleunigt ablaufen. Nach dem biologischen Artkonzept sind Arten Fortpflanzungsgemeinschaften. Ob zwei am selben Ort vorkommende Formen Arten sind, lĂ€sst sich also unschwer feststellen. Überlappen ihre Verbreitungsgebiete jedoch nicht, kann ein Aufeinandertreffen mit Hilfe von Klangattrappenversuchen simuliert werden. Ansonsten bleibt – auch auf ĂŒberartlichem Niveau – nur der Vergleich homologer LautĂ€ußerungen: Er kann deskriptiv nach Höreindruck oder auf Grund der Visualisierung (Sonagramm) oder statistisch mit Hilfe verschiedener dem Sonagramm entnommener Parameter erfolgen. Sofern eine (molekulare) Phylogenie der betreffenden Gattung oder Familie vorliegt, sollten die herangezogenen Parameter auf phylogenetisches Signal hin getestet werden, um rein adaptive Merkmale auszuschließen.Bird vocalizations connected to reproduction are mostly species-specific, hence they may be used as taxonomic characters. They have special relevance when in bird species which are able to learn song speciation processes at an accelerated pace. According to the biological species concept, species are populations which are reproductively isolated from other populations. Thus it can easily be decided, if two forms occurring in the same place are species. But if their distributions do not overlap, a contact can be simulated by means of playback experiments. Otherwise homologous vocalizations have to be compared – like on a supra-specific level: Such comparisons may be performed descriptively according to auditory impression, or based on the visualization (sonagram), or statistically on parameters measured from the sonagram. In case a (molecular) phylogeny of the genus or family under investigation is available, the analyzed parameters should be tested for phylogenetic signal to exclude merely adaptive characters

    On Modeling a Social Networking Service Description

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    “They just won't listen”—The role of blame in narratives of past extreme weather events for anticipating future crisis

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    The phase before an extreme weather event is crucial for the actual reaction to the impacts of such an event. In this phase, professionals in the field of civil protection and emergency management anticipate the intensity and impact of the event and use these expectations for action. We argue that anticipation is—beyond others—shaped by the organizations’ shared narratives of past crisis that resulted from extreme weather events. The findings focus on the frame of ‘blame’ in the narration and are based on two fields of study, road maintenance services and forest fire control. Qualitative group discussions and semistructured interviews show two very different views on blame depending on the organization: human factors and fate. This contrast can be traced back to the character of the weather events itself, but also with the self-image of the organization and perceived external expectations. Depending on the narrative plot and threshold of the event, narratives can affect and alter practices of anticipation through narrations of renewal. Findings contribute to the understanding of organizational sensemaking through narratives of blame and consequences

    Requirements for the use of impact-based forecasts and warnings by road maintenance services in Germany

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    Impact-based forecasts and warnings (IBFs) are seen as important drivers for adequate anticipation and assessment of potential threats to public safety as they give a better understanding of the weather event's impacts. To prepare for impacts of weather events and prevent weather-related accidents, road maintenance services are actively using weather information in their daily work routine. This paper looks into the requirements that road maintenance services have for IBFs and how weather forecasts are used at the moment. The study is part of an interdisciplinary research project and follows a qualitative social science research approach. Findings show that the following factors are general user requirements: relevance of information, recognition of spatial and temporal requests, acceptability, comprehensibility, and technical demands. These are also applicable to IBFs with the extension to provide a benefit for road maintenance services in situations that rarely occur and where no embodied knowledge in the organization is existent

    Molecular monitoring of minimal residual disease in two patients with MLL-rearranged acute myeloid leukemia and haploidentical transplantation after relapse

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    This report describes the clinical courses of two acute myeloid leukemia patients. Both had MLL translocations, the first a t(10;11)(p11.2;q23) with MLL-AF10 and the second a t(11;19)(q23;p13.1) with MLL-ELL fusion. They achieved a clinical remission under conventional chemotherapy but relapsed shortly after end of therapy. Both had a history of invasive mycoses (one had possible pulmonary mycosis, one systemic candidiasis). Because no HLA-identical donor was available, a haploidentical transplantation was performed in both cases. Using a specially designed PCR method for the assessment of minimal residual disease (MRD), based on the quantitative detection of the individual chromosomal breakpoint in the MLL gene, all patients achieved complete and persistent molecular remission after transplantation. The immune reconstitution after transplantation is described in terms of total CD3+/CD4+, CD3+/CD8+, CD19+, and CD16+/CD56+ cell numbers over time. The KIR and HLA genotypes of donors and recipients are reported and the possibility of a KIR-mediated alloreactivity is discussed. This report illustrates that haploidentical transplantation may offer a chance of cure without chronic graft-versus-host disease in situations where no suitable HLA-identical donor is available even in a high-risk setting and shows the value of MRD monitoring in the pre- and posttransplant setting

    Permeation control in hydrogel-layered patterned PET membranes with defined switchable pore geometry – Experiments and numerical simulation

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    AbstractPermeation through polymeric membranes can be controlled by surface coating of a polyethylene terephthalate (PET) membrane with poly(N-isopropylacrylamide) (PNIPAAm) and inserting pores of defined geometry. When the temperature of the system rises above the volume phase transition temperature, the pores open, which allows permeation of formerly blocked particles. The exact control of the temperature allows defined change of the pore size and therefore enables separation abilities. Free swelling experiments are conducted to obtain the swelling behaviour of PNIPAAm. Then, a temperature expansion model is derived in order to simulate this behaviour with the finite element tool ABAQUS. The gained results are in excellent agreement with the observed shape change. Membranes with permeation control of particles can be used for biomedical application in microfluidics to analyse the size distribution of cells or in chemical information processing as a transistor-like component for an information-bearing chemical species. The possibility to simulate the behaviour of such permeation systems allows computer aided design and prediction of permeation abilities in these areas

    The Systemic Management of Advanced Melanoma in 2016

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    Melanoma is a common type of skin cancer with a high propensity to metastasize. Tyrosine kinase inhibitors targeting the mitogen-activated protein kinase (MAPK) pathway and immune checkpoint blockade have recently revolutionized the management of unresectable and metastatic disease. However, acquired resistance and primary non-response to therapy require novel treatment strategies and combinations. The purpose of this review is to provide a brief and up-to-date overview on the clinical management and current trial landscape in melanoma. We summarize the most pertinent studies on BRAF/MEK inhibitors and blockade of cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1). Although most agents show robust antitumor efficacy as single agents, further improvements have been achieved by the combination of both approved and developing drugs. We discuss ongoing trials and evaluate future approaches that may provide additional efficacy with less toxicity. (C) 2016 S. Karger GmbH, Freibur

    Bird handling techniques and data acquisition in the tropics and subtropics

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    Der Fang von Vögeln zu wissenschaftlichen Zwecken in den Tropen und Subtropen stellt eine Herausforderung fĂŒr Ornithologen dar. Probleme aufgrund rechtlicher sowie sozioökonomischer und soziokultureller Rahmenbedingungen lassen sich oft durch eine intensive Vorbereitung und Kooperationen mit lokalen Partnern vermeiden oder reduzieren. Beim eigentlichen Fang sind logistische Herausforderungen wie die Materialbeschaffung vor Ort, aber auch die Ökologie einiger ĂŒberwiegend tropischer Vogelgruppen zu berĂŒcksichtigen. Hier wie auch bei der Probennahme und -lagerung beeinflussen die herrschenden Umweltbedingungen die Arbeit, insbesondere extreme Witterung. Problemlösungenlassen sich jedoch teilweise nur schwer verallgemeinern. Wir unterstreichen die Bedeutung lokaler und regionaler Besonderheiten anhand zahlreicher Beispiele aufgrund eigener Erfahrungen.Capturing birds for scientific purposes in tropical and subtropical areas is particularly challenging. Problems due to general judicial, socio-economic and socio-cultural conditions can often be avoided or reduced by an intensive prearrangement and cooperation with local partners. When actually capturing birds, logistical challenges, differences in predation and the ecology of specific tropical bird groups need to be considered. In this respect and also for sampling and sample storage, environmental conditions, especially extreme weather conditions, are factors to be considered. Troubleshooting and resolving issues related to ornithology in the tropical biomes is not always straightforward. Here we emphasize the importance of local and regional peculiarities by numerous examples based on our own experiences

    Feel the heat: Nonlinear electrothermal feedback in organic LEDs

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    For lighting applications, Organic light-emitting diodes (OLED) need much higher brightness than for displays, leading to self-heating. Due to the temperature-activated transport in organic semiconductors, this can result in brightness inhomogeneities and catastrophic failure. Here, we show that due to the strong electrothermal feedback of OLEDs, the common spatial current and voltage distribution is completely changed, requiring advanced device modeling and operation concepts. Our study clearly demonstrates the effect of negative differential resistance (NDR) in OLEDs induced by self-heating. As a consequence, for increasing voltage, regions with declining voltages are propagating through the device, and even more interestingly, a part of these regions show even decreasing currents, leading to strong local variation in luminance. The expected breakthrough of OLED lighting technology will require an improved price performance ratio, and the realization of modules with very high brightness but untainted appearance is considered to be an essential step into this direction. Thus, a deeper understanding of the control of electrothermal feedback will help to make OLEDs in lighting more competitive
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