5,201 research outputs found

    Siphonaptera Records and Host Associations From the Central and Eastern Upper Peninsula of Michigan

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    Fleas were collected from birds and mammals over a five year period in four upper peninsula counties. Identified specimens were compared to published records of distribution for the parasite species and its host species, and only those records which are new county distributions for host or parasite are listed. Four new host records for Michigan, four new flea distribution records for the upper peninsula, and 26 new county records are listed

    Sanskrit Lexical Sources: Digital Synthesis and Revision

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    The proposed project aims to synthesize, extend, revise, and improve the principal lexical reference works of Sanskrit, one of the world's richest culture-bearing languages, and to provide wide public access to them in the digital Sanskrit library

    Using effective medium theories to design tailored nanocomposite materials for optical systems

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    Modern optical systems are subject to very restrictive performance, size and cost requirements. Especially in portable systems size often is the most important factor, which necessitates elaborate designs to achieve the desired specifications. However, current designs already operate very close to the physical limits and further progress is difficult to achieve by changing only the complexity of the design. Another way of improving the performance is to tailor the optical properties of materials specifically to the application at hand. A class of novel, customizable materials that enables the tailoring of the optical properties, and promises to overcome many of the intrinsic disadvantages of polymers, are nanocomposites. However, despite considerable past research efforts, these types of materials are largely underutilized in optical systems. To shed light into this issue we, in this paper, discuss how nanocomposites can be modeled using effective medium theories. In the second part, we then investigate the fundamental requirements that have to be fulfilled to make nanocomposites suitable for optical applications, and show that it is indeed possible to fabricate such a material using existing methods. Furthermore, we show how nanocomposites can be used to tailor the refractive index and dispersion properties towards specific applications.Comment: This is a draft manuscript of a paper published in Proc. SPIE (Proceedings Volume 10745, Current Developments in Lens Design and Optical Engineering XIX, Event: SPIE Optical Engineering + Applications, 2018

    Isotope shift in the Sulfur electron affinity: observation and theory

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    The electron affinities eA(S) are measured for the two isotopes 32S and 34S (16752.9753(41) and 16752.9776(85) cm-1, respectively). The isotope shift in the electron affinity is found to be positive, eA(34S)-eA(32S) = +0.0023(70) cm-1, but the uncertainty allows for the possibility that it may be either "normal" (eA(34S) > eA(32S)) or "anomalous" (eA(34S) < eA(32S)). The isotope shift is estimated theoretically using elaborate correlation models, monitoring the electron affinity and the mass polarization term expectation value. The theoretical analysis predicts a very large specific mass shift that counterbalances the normal mass shift and produces an anomalous isotope shift, eA(34S)-eA(32S) = - 0.0053(24) cm-1. The observed and theoretical residual isotope shifts agree with each other within the estimated uncertainties.Comment: 15 pages, 4 figure

    Localization of proteasomes and proteasomal proteolysis in the mammalian interphase cell nucleus by systematic application of immunocytochemistry

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    Proteasomes are ATP-driven, multisubunit proteolytic machines that degrade endogenous proteins into peptides and play a crucial role in cellular events such as the cell cycle, signal transduction, maintenance of proper protein folding and gene expression. Recent evidence indicates that the ubiquitin-proteasome system is an active component of the cell nucleus. A characteristic feature of the nucleus is its organization into distinct domains that have a unique composition of macromolecules and dynamically form as a response to the requirements of nuclear function. Here, we show by systematic application of different immunocytochemical procedures and comparison with signature proteins of nuclear domains that during interphase endogenous proteasomes are localized diffusely throughout the nucleoplasm, in speckles, in nuclear bodies, and in nucleoplasmic foci. Proteasomes do not occur in the nuclear envelope region or the nucleolus, unless nucleoplasmic invaginations expand into this nuclear body. Confirmedly, proteasomal proteolysis is detected in nucleoplasmic foci, but is absent from the nuclear envelope or nucleolus. The results underpin the idea that the ubiquitin-proteasome system is not only located, but also proteolytically active in distinct nuclear domains and thus may be directly involved in gene expression, and nuclear quality control. © 2007 Springer-Verlag

    Toxicity Assessment of Energetic Materials by Using the Luminescent Bacteria Inhibition Test

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    The luminescent bacteria inhibition test usingAliivibrio fischeriis a well-established method to determine the aquatic toxicity of soluble chemicals. More precisely, the effective concentration (EC50) after 15 and 30 min is determined in this test. The inhibition of natural bioluminescence of these bacteria gives a first idea of the toxicity of compounds towards some aquatic organisms. It is a cost and time efficient experimental method, which does not involve animals. In this contribution, the experimental set up, comparability with other measurements, and results of recently described compounds is presented. Different types of energetic materials such as coordination (e. g. [Cu(dtp)(3)](ClO4)(2)and [Fe(MTZ)(6)](ClO4)(2)), neutral (e. g. azidoethanol, 1- and 2-aminotetrazole) and ionic (e. g. polynitropyrazolates and PETNC salts) compounds were investigated and compared to commonly used materials, like RDX, ammonium perchlorate (AP) and azide salts. Furthermore, different substitution patterns and energetic functionalities such as azido-, nitro- and nitramino-groups were investigated

    Anodisation of Aluminium Alloys by Micro-Capillary Technique as a Tool for Reliable, Cost-Efficient, and Quick Process Parameter Determination

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    Anodisation is essential for improving surface properties of aluminium alloys and composites regarding wear and corrosion behaviour. Optimisation of the anodising process depends on microstructural constituents contained in aluminium alloys and represents a key task, consisting of the control of process parameters and electrolyte formulation. We applied the micro-capillary technique known from corrosion studies and modified it to form anodic aluminium oxide films on high-strength aluminium alloys in comparison to pure aluminium in sulphuric acid. A glass capillary with an opening of 800 μm in diameter was utilized. Corresponding electrochemical measurements during potentiodynamic and potentiostatic anodisation revealed anodic current responses similar to conventional anodisation. The measurement of film thickness was adapted to the thin anodised spots using ellipsometry and energy dispersive X-ray analysis. Cross sections prepared by focused ion beam milling confirm the thickness results and show the behaviour of intermetallic phases depending on the anodising potential. Consequently, micro-capillary anodising proved to be an effective tool for developing appropriate anodisation conditions for aluminium alloys and composites because it allows quick variation of electrolyte composition by applying low electrolyte volumes and rapid film formation due to short process durations at small areas and more flexible variation of process parameters due to the used set-up

    Connecting at Local Level: Exploring Opportunities for Future Design of Technology to Support Social Connections in Age-friendly Communities

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    Social connectedness in later life is an important dimension of an age-friendly community, with associated implications for individual health and wellbeing. In contrast with prior efforts focusing on connections at a distance or online communities where the digital technology is the interface, we explore the design opportunities and role of technology for connectedness within a geographically local community context. We present findings from interviews with 22 older adults and a linked ideation workshop. Our analysis identified shared concerns and negative perceptions around local relationships, connections and characteristics of the geographical area. However, local connectedness through technology was largely absent from day-to-day life and even perceived as contributing to disconnection. By uncovering how older adults use and perceive technology in their social lives and combining these findings with their ideas for improving local connections, we highlight the need for thoughtful consideration of the role of technology in optimising social connections within communities. Our research highlights a need for design work to understand the specifics of the local context and reduce emphasis on technology as the interface between people. We introduce an amended definition&mdash;&lsquo;underpinned by a commitment to respect and social inclusion, an age-friendly community is engaged in a strategic and ongoing process to facilitate active ageing by optimising the community&rsquo;s physical, social and digital environments and its supporting infrastructure&rsquo;&mdash;to conceptualise our approach. We conclude by suggesting areas for future work in developing digitally connected age-friendly communities

    The Akademii Nauk ice core and solar activity

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    Ice cores are well established archives for paleo-environmental studies, but this requires a reliable ice core chronology. The concentration of cosmogenic radionuclides in ice cores reflects the solar activity in the past and can be used as dating tool for ice cores. Accelerator mass spectrometry (AMS) allows the determination of nuclides in high resolution. Here we present results of a 10Be study in an ice core from Akademii Nauk (Severnaya Zemlya, Russian Arctic). AMS analyses of more than 500 samples were carried out using the 6 MV accelerator facility of the Ion Beam Centre of the Helmholtz-Zentrum Dresden-Rossendorf. For the time period 400 to 2000 CE the temporal variations of 10Be reflect the centennial variations of solar activity known from similar studies of Greenlandic ice cores and from 14C production reconstructions. The 10Be peak of 775 CE, today understood as result of the strongest known solar particle storm, was found by high resolution core analysis. This peak is used as tie point (additionally to volcanic reference horizons) for the development of the depth-age relationship of the Akademii Nauk ice core. Indications of the so called “Carrington Event” of 1859 CE, 20 to 30 times weaker than 775 CE, could also be detected in the core
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