24 research outputs found

    Fauna Europaea: Diptera -Brachycera

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    Link to publication Citation for published version (APA): Pape, T., Beuk, P., Pont, A. C., Shatalkin, A. I., Ozerov, A. L., WoĆșnica, A. J., ... de Jong, Y. (2015). Fauna Europaea: 3, [e4187]. https://doi.org/10.3897/BDJ.3.e4187 General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Abstract Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all extant multicellular European terrestrial and freshwater animals and their geographical distribution at the level of countries and major islands (east of the Urals and excluding the Caucasus region). The Fauna Europaea project comprises about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. Fauna Europaea represents a huge effort by more than 400 contributing taxonomic specialists throughout Europe and is a unique (standard) reference suitable for many user communities in science, government, industry, nature conservation and education. The Diptera-Brachycera is one of the 58 Fauna Europaea major taxonomic groups, and data have been compiled by a network of 55 specialists. Within the two-winged insects (Diptera), the Brachycera constitute a monophyletic group, which is generally given rank of suborder. The Brachycera may be classified into the probably paraphyletic 'lower brachyceran grade' and the monophyletic Eremoneura. The latter contains the Empidoidea, the Apystomyioidea with a single Nearctic species, and the Cyclorrhapha, which in turn is divided into the paraphyletic 'aschizan grade' and the monophyletic Schizophora. The latter is traditionally divided into the paraphyletic 'acalyptrate grade' and the monophyletic Calyptratae. Our knowledge of the European fauna of Diptera-Brachycera varies tremendously among families, from the reasonably well known hoverflies (Syrphidae) to the extremely poorly known scuttle flies (Phoridae). There has been a steady growth in our knowledge of European Diptera for the last two centuries, with no apparent slow down, but there is a shift towards a larger fraction of the new species being found among the families of the nematoceran grade (lower Diptera), which due to a larger number of small-sized species may be considered as taxonomically more challenging. Most of Europe is highly industrialised and has a high human population density, and the more fertile habitats are extensively cultivated. This has undoubtedly increased the extinction risk for numerous species of brachyceran flies, yet with the recent re-discovery of Thyreophora cynophila (Panzer), there are no known cases of extinction at a European level. However, few national Red Lists have extensive information on Diptera. For the Diptera-Brachycera, data from 96 families containing 11,751 species are included in this paper

    Ca<sub>11</sub>E<sub>3</sub>C<sub>8</sub> (E = Sn, Pb): New Complex Carbide Zintl Phases Grown from Ca/Li Flux

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    New carbide Zintl phases Ca<sub>11</sub>E<sub>3</sub>C<sub>8</sub> (E = Sn, Pb) were grown from reactions of carbon and heavy tetrelides in Ca/Li flux. They form with a new structure type in space group <i>P</i>2<sub>1</sub>/<i>c</i> (<i>a</i> = 13.1877(9)­Å, <i>b</i> = 10.6915(7)­Å, <i>c</i> = 14.2148(9)­Å, ÎČ = 105.649(1)°, and <i>R</i><sub>1</sub> = 0.019 for the Ca<sub>11</sub>Sn<sub>3</sub>C<sub>8</sub> analog). The structure features isolated E<sup>4–</sup> anions as well as acetylide (C<sub>2</sub><sup>2–</sup>) and allenylide (C<sub>3</sub><sup>4–</sup>) anions; the vibrational modes of the carbide anions are observed in the Raman spectrum. The charge-balanced nature of these phases is confirmed by DOS calculations which indicate that the tin analog has a small band gap (<i>E</i><sub>g</sub> < 0.1 eV) and the lead analog has a pseudogap at the Fermi level. Reactions of these compounds with water produce acetylene and allene

    Reaction of Methane with Bulk Intermetallics Containing Iron Clusters Yields Carbon Nanotubes

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    Reaction of Methane with Bulk Intermetallics Containing Iron Clusters Yields Carbon Nanotube

    Ca<sub>11</sub>E<sub>3</sub>C<sub>8</sub> (E = Sn, Pb): New Complex Carbide Zintl Phases Grown from Ca/Li Flux

    No full text
    New carbide Zintl phases Ca<sub>11</sub>E<sub>3</sub>C<sub>8</sub> (E = Sn, Pb) were grown from reactions of carbon and heavy tetrelides in Ca/Li flux. They form with a new structure type in space group <i>P</i>2<sub>1</sub>/<i>c</i> (<i>a</i> = 13.1877(9)­Å, <i>b</i> = 10.6915(7)­Å, <i>c</i> = 14.2148(9)­Å, ÎČ = 105.649(1)°, and <i>R</i><sub>1</sub> = 0.019 for the Ca<sub>11</sub>Sn<sub>3</sub>C<sub>8</sub> analog). The structure features isolated E<sup>4–</sup> anions as well as acetylide (C<sub>2</sub><sup>2–</sup>) and allenylide (C<sub>3</sub><sup>4–</sup>) anions; the vibrational modes of the carbide anions are observed in the Raman spectrum. The charge-balanced nature of these phases is confirmed by DOS calculations which indicate that the tin analog has a small band gap (<i>E</i><sub>g</sub> < 0.1 eV) and the lead analog has a pseudogap at the Fermi level. Reactions of these compounds with water produce acetylene and allene

    High-efficiency Superconducting Single-photon Detectors

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    Superconducting single-photon detectors have been shown to have extremely high detection efficiency over a large wavelength range, typically exceeding 90 % [1, 2]. Their use in quantum and classical optics is becoming more and more widespread in part due to improvements to and ease of use of the cryogenic packaging. In this talk, we will review two superconducting detector technologies, the superconducting nanowire single-photon detector (SNSPD) and the optical transition-edge sensor (TES) [3], that are being developed at NIST. We will also describe their applications in quantum and classical optics and present our recent effort to use these detectors as calibration standards, as well as our effort to establish a single-photon detector calibration service. Superconducting Nanowire Single Photon Detectors The SNSPD is based on a meandering, narrow, thin superconducting nanowire, current-biased close to its critical current. Our SNSPDs operate at temperatures around 1K. When a photon is absorbed in the detection region, the energy deposited drives the wire normal and a voltage pulse can be observed. Due to the speed of the detection process, the SNSPD offers high timing resolution along with detection of the photon flux at the shot-noise limit. The combination of both these features yields a detector that can measure the photon’s arrival time from a faint object or source. SNSPDs also offer single-photon detection capability beyond the wavelength detection range of silicon and InGaAs, out to at least 5000 nm [4]. SNSPDs were also recently implemented in an 8×8-pixel array enabling low-resolution, real-time imaging [5]. For our calibration service effort, we built an SNSPD system that can be used as a transfer standard between labs for single-photon detector calibrations. Transition Edge Sensors In contrast to the SNSPD, the TES is a photon-number resolving detector that has almost unity detection efficiency. The TES consists of a superconducting thin film, voltage-biased so that its resistance is in the transition between the superconducting regime and the normal conducting regime. The steep slope of the resistive transition allows for small temperature changes to be measured. The TES is designed such that the absorption of a single photon increases the temperature of the superconducting film enough to discern the resulting signal from the TES system noise. Therefore, the TES needs to be electrically and thermally quiet and is generally operated at temperatures around 100 mK. Due to its energy resolving capability, the TES can be also used as a spectrally resolving single-photon detector with limited resolution [6]. The TES can also be operated as a cryogenic radiometer in combination with an electrical substitution method, and can, in principle, yield absolute calibration of optical powers on the order of a few tens of femtowatts [7]. References 1 A. E. Lita, A. J. Miller, and S. W. Nam, Opt. Express 16, 3032 (2008). 2 F. Marsili, et al., Nat Photon 7, 210 (2013). 3 R. Hadfield and G. Johansson, Superconducting Devices in Quantum Optics (Springer, 2016). 4 F. Marsili, et al., in CLEO: 2013 (OSA, San Jose, California, 2013), p. CTu1H.1. 5 M. S. Allman, et al., Applied Physics Letters 106, 192601 (2015). 6 M. Fortsch, et al., Journal of Optics 17, 065501 (2015). 7 N. A. Tomlin, J. H. Lehman, and S. Nam, Optics Letters 37, 2346 (2012)

    Detection of Metabolic Changes Induced via Drug Treatments in Live Cancer Cells and Tissue Using Raman Imaging Microscopy

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    Isocitrate dehydrogenase 1 (IDH1) mutations in gliomas, fibrosarcoma, and other cancers leads to a novel metabolite, D-2-hydroxyglutarate, which is proposed to cause tumorigenesis. The production of this metabolite also causes vulnerabilities in cellular metabolism, such as lowering NADPH levels. To exploit this vulnerability, we treated glioma and fibrosarcoma cells that harbor an IDH1 mutation with an inhibitor of nicotinamide adenine dinucleotide (NAD+) salvage pathway, FK866, and observed decreased viability in these cells. To understand the mechanism of action by which the inhibitor FK866 works, we used Raman imaging microscopy and identified that proteins and lipids are decreased upon treatment with the drug. Raman imaging showed a different distribution of lipids throughout the cell in the presence of the drug compared with the untreated cells. We employed nuclear magnetic resonance NMR spectroscopy and mass spectrometry to identify the classes of lipids altered. Our combined analyses point to a decrease in cell division due to loss of lipid content that contributes to membrane formation in the in vitro setting. However, the FK866 drug did not have the same potency in vivo. The use of Raman imaging microscopy indicated an opposite trend of lipid distribution in the tissue collected from treated versus untreated mice when compared with the cells. These results demonstrate the role of Raman imaging microscopy to identify and quantify metabolic changes in cancer cells and tissue

    Microwave-Specific Enhancement of the Carbon–Carbon Dioxide (Boudouard) Reaction

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    The Boudouard reaction, which is the reaction of carbon and carbon dioxide to produce carbon monoxide, represents a simple and straightforward method for the remediation of carbon dioxide in the environment through reduction: CO<sub>2</sub>(g) + C(s) ⇌ 2CO. However, due to the large positive enthalpy, typically reported to be 172 kJ/mol under standard conditions at 298 K, the equilibrium does not favor CO production until temperatures >700 °C, when the entropic term, −<i>T</i>Δ<i>S</i>, begins to dominate and the free energy becomes negative. We have found that, under microwave irradiation to selectively heat the carbon, dramatically different thermodynamics for the reaction are observed. During kinetic studies of the reaction under conditions of flowing CO<sub>2</sub>, the apparent activation energy dropped from 118.4 kJ/mol under conventional convective heating to 38.5 kJ/mol under microwave irradiation. From measurement of the equilibrium constants as a function of temperature, the enthalpy of the reaction dropped from 183.3 kJ/mol at ∌1100 K to 33.4 kJ/mol at the same temperature under microwave irradiation. This changes the position of the equilibrium so that the temperature at which CO becomes the major product drops from 643 °C in the conventional thermal reaction to 213 °C in the microwave. The observed reduction in the apparent enthalpy of the microwave driven reaction, compared to what is determined for the thermal reaction from standard heats of formation, can be thought of as arising from additional energy being put into the carbon by the microwaves, effectively increasing its apparent standard enthalpy. Mechanistically, it is hypothesized that the enhanced reactivity arises from the interaction of CO<sub>2</sub> with the steady-state concentration of electron–hole pairs that are present at the surface of the carbon due to the space-charge mechanism, by which microwaves are known to heat carbon. Such a mechanism is unique to microwave-induced heating and, given the effect it has on the thermodynamics of the Boudouard reaction, suggests that its use may yield energy savings in driving the general class of gas–carbon reactions

    Metabolic Landscape of a Genetically Engineered Mouse Model of IDH1 Mutant Glioma

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    Understanding the metabolic reprogramming of aggressive brain tumors has potential applications for therapeutics as well as imaging biomarkers. However, little is known about the nutrient requirements of isocitrate dehydrogenase 1 (IDH1) mutant gliomas. The IDH1 mutation involves the acquisition of a neomorphic enzymatic activity which generates D-2-hydroxyglutarate from &alpha;-ketoglutarate. In order to gain insight into the metabolism of these malignant brain tumors, we conducted metabolic profiling of the orthotopic tumor and the contralateral regions for the mouse model of IDH1 mutant glioma; as well as to examine the utilization of glucose and glutamine in supplying major metabolic pathways such as glycolysis and tricarboxylic acid (TCA). We also revealed that the main substrate of 2-hydroxyglutarate is glutamine in this model, and how this re-routing impairs its utilization in the TCA. Our 13C tracing analysis, along with hyperpolarized magnetic resonance experiments, revealed an active glycolytic pathway similar in both regions (tumor and contralateral) of the brain. Therefore, we describe the reprogramming of the central carbon metabolism associated with the IDH1 mutation in a genetically engineered mouse model which reflects the tumor biology encountered in glioma patients

    Mechanism of Initiation in the Phillips Ethylene Polymerization Catalyst: Redox Processes Leading to the Active Site

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    The detailed mechanism by which ethylene polymerization is initiated by the inorganic Phillips catalyst (Cr/SiO<sub>2</sub>) without recourse to an alkylating cocatalyst remains one of the great unsolved mysteries of heterogeneous catalysis. Generation of the active catalyst starts with reduction of Cr<sup>VI</sup> ions dispersed on silica. A lower oxidation state, generally accepted to be Cr<sup>II</sup>, is required to activate ethylene to form an organoCr active site. In this work, a mesoporous, optically transparent monolith of Cr<sup>VI</sup>/SiO<sub>2</sub> was prepared using sol–gel chemistry in order to monitor the reduction process spectroscopically. Using in situ UV–vis spectroscopy, we observed a very clean, stepwise reduction by CO of Cr<sup>VI</sup> first to Cr<sup>IV</sup>, then to Cr<sup>II</sup>. Both the intermediate and final states show XANES consistent with these oxidation state assignments, and aspects of their coordination environments were deduced from Raman and UV–vis spectroscopies. The intermediate Cr<sup>IV</sup> sites are inactive toward ethylene at 80 °C. The Cr<sup>II</sup> sites, which have long been postulated as the end point of CO reduction, were observed directly by high-frequency/high-field EPR spectroscopy. They react quantitatively with ethylene to generate the organoCr<sup>III</sup> active sites, characterized by X-ray absorption and UV–vis spectroscopy, which initiate polymerization
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