1,295 research outputs found

    A theoretical simulation of the resonant Raman spectroscopy of the H2O⋯Cl2 and H2O⋯Br2 halogen-bonded complexes

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    The resonant Raman spectra of the H2O⋯Cl2 and H2O⋯Br2 halogen-bonded complexes have been studied in the framework of a 2-dimensional model previously used in the simulation of their UV-visible absorption spectra using time-dependent techniques. In addition to the vibrational progression along the dihalogen mode, a progression is observed along the intermolecular mode and its combination with the intramolecular one. The relative intensity of the inter to intramolecular vibrational progressions is about 15% for H2O⋯Cl2 and 33% for H2O⋯Br2. These results make resonant Raman spectra a potential tool for detecting the presence of halogen bonded complexes in condensed phase media such as clathrates and ice.Fil: Franklin Mergarejo, Ricardo. Université Paris Sud; Francia. Centre National de la Recherche Scientifique; Francia. InSTEC; Cuba. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rubayo Soneira, Jesús. InSTEC; CubaFil: Halberstadt, Nadine. Université Paris Sud; Francia. Centre National de la Recherche Scientifique; FranciaFil: Janda, Kenneth C.. University of California at Irvine; Estados UnidosFil: Apkarian, V. Ara. University of California at Irvine; Estados Unido

    Basel II, External Ratings and Adverse Selection

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    This paper will describe and analyse the development of Basel II Capital Accord and will focus on the use of external ratings in the Standardized Approach in Basel II. Furthermore it will examine the problem of adverse selection which appears in Basel II as a result from the proposal for the use of external ratings in determining the risk weights in the standardized approach. The paper will also attempt to find possible solutions to the adverse selection problem by discussing two similar models, and derive implications from them.Basel II, external ratings, adverse selection, rating agencies, standardized approach

    Beyond feedback: introducing the 'engagement gap' in organizational energy management

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    This paper discusses socio-technical relationships between people, organizations and energy in workplaces. Inspired by Sherry Arnstein’s ladder of citizen participation, it explores widening energy management beyond energy managers to other employees, introducing the idea of an ‘engagement gap’ to support a move beyond unidirectional forms of engagement (e.g. feedback and nudging) to more socially interactive processes. Results are drawn from two projects researching energy practices in public authorities and retail organizations. The first project, ‘GoodDeeds’, collaboratively created an information and communication technology tool and explored participatory processes within a municipality. The second project, Working with Infrastructure, Creation of Knowledge, and Energy strategy Development (WICKED), explored energy management in retail companies. The paper uses a ‘4Cs’ framework to articulate the influences of concerns, capacities and technical conditions within organizational communities. The results concur with previous research that energy management sits against a backdrop of competing organizational, institutional and political concerns. New data reveal discrepancies across organizations with regard to energy management capacities and technical metering conditions. The authors suggest employee engagement can be broadened by treating energy as a communal subject for discussion, negotiation and partnership. This objective moves beyond the ‘information-deficit’ approach intrinsic in the existing focus on analytics, dashboards and feedback

    Holomorphic anomaly equations and the Igusa cusp form conjecture

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    Let SS be a K3 surface and let EE be an elliptic curve. We solve the reduced Gromov-Witten theory of the Calabi-Yau threefold S×ES \times E for all curve classes which are primitive in the K3 factor. In particular, we deduce the Igusa cusp form conjecture. The proof relies on new results in the Gromov-Witten theory of elliptic curves and K3 surfaces. We show the generating series of Gromov-Witten classes of an elliptic curve are cycle-valued quasimodular forms and satisfy a holomorphic anomaly equation. The quasimodularity generalizes a result by Okounkov and Pandharipande, and the holomorphic anomaly equation proves a conjecture of Milanov, Ruan and Shen. We further conjecture quasimodularity and holomorphic anomaly equations for the cycle-valued Gromov-Witten theory of every elliptic fibration with section. The conjecture generalizes the holomorphic anomaly equations for ellliptic Calabi-Yau threefolds predicted by Bershadsky, Cecotti, Ooguri, and Vafa. We show a modified conjecture holds numerically for the reduced Gromov-Witten theory of K3 surfaces in primitive classes.Comment: 68 page

    Carbodiimide and Isocyanate Hydroboration by a Cyclic Carbodiphosphorane Catalyst

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    We report hydroboration of carbodiimide and isocyanate substrates catalyzed by a cyclic carbodiphosphorane catalyst. The cyclic carbodiphosphorane outperformed the other Lewis basic carbon species tested, including other zerovalent carbon compounds, phosphorus ylides, an N-heterocyclic carbene, and an N-heterocyclic olefin. Hydroborations of seven carbodiimides and nine isocyanates were performed at room temperature to form N-boryl formamidine and N-boryl formamide products. Intermolecular competition experiments demonstrated the selective hydroboration of alkyl isocyanates over carbodiimide and ketone substrates. DFT calculations support a proposed mechanism involving activation of pinacolborane by the carbodiphosphorane catalyst, followed by hydride transfer and B−N bond formation

    Towards inclusive urban building energy models: incorporating slum-dwellers and informal settlements (IN-UBEMs)

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    Urban building energy models (UBEMs) are emerging as a data-driven method for predicting energy consumption and assessing the impacts of policies aimed at reducing carbon emissions in cities. To date, the majority of these models have been developed for cities in the global north where urbanisation rates are relatively slow, the building stock turnover is low and data are relatively easy to obtain. As their use expands, they are being applied in faster-growing urban areas in the global south, where considerable investment is planned in capital infrastructure. This paper focuses on slums, which include populations that are hard to reach, underserved by current energy systems, and largely absent from UBEMs. It asks: what are the social, economic, and environmental implications of excluding slum dwellers and informal settlements from UBEMs used for policy development? If existing UBEMs do not adequately capture the needs of low-income urban residents, then planning decisions based on these models risk both carbon lock-in and deepening poverty for already marginalised groups. To redress these problems, this paper considers three key questions: 1. how informal settlements and low-income groups have been represented in UBEMs to date and the potential implications of their exclusion; 2. the politics, norms and behaviours of energy supply and demand within informal settlements; 3. what issues should be explored to integrate these marginalized housing groups within UBEMs. In conclusion, it calls for additional social science research to reduce the impacts of exclusion and to co-produce new methodologies with energy modellers. Future steps include fostering ongoing engagement with both expert and non-expert populations to facilitate citizen participation in evidence-based planning decisions

    Basel II, External Ratings and Adverse Selection

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    This paper will describe and analyse the development of Basel II Capital Accord and will focus on the use of external ratings in the Standardized Approach in Basel II. Furthermore it will examine the problem of adverse selection which appears in Basel II as a result from the proposal for the use of external ratings in determining the risk weights in the standardized approach. The paper will also attempt to find possible solutions to the adverse selection problem by discussing two similar models, and derive implications from them

    Basel II, External Ratings and Adverse Selection

    Get PDF
    This paper will describe and analyse the development of Basel II Capital Accord and will focus on the use of external ratings in the Standardized Approach in Basel II. Furthermore it will examine the problem of adverse selection which appears in Basel II as a result from the proposal for the use of external ratings in determining the risk weights in the standardized approach. The paper will also attempt to find possible solutions to the adverse selection problem by discussing two similar models, and derive implications from them

    COVID-19: treatment strategies of German-speaking pediatric rheumatologists Results of an online survey

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    Zusammenfassung Hintergrund Zuverlässige Daten zu Verlauf und Therapie von COVID-19 („corona virus disease 2019“) bei Kindern mit rheumatischen Erkrankungen unter Immunsuppression fehlen. Ziel der Arbeit Abbildung individueller Strategien der Mitglieder der Gesellschaft für Kinder- und Jugendrheumatologie (GKJR) im Umgang mit COVID-19. Methodik Mittels Online-Umfrage wurden im Mai 2020 das Meinungsbild der GKJR-Mitglieder zum Umgang mit DMARDs („disease-modifying anti-rheumatic drugs“) bei COVID-19-Erkrankung sowie die Bereitschaft zum Einsatz spezieller Therapieansätze bei Patienten mit unterschiedlicher Schwere von COVID-19 erhoben. Ergebnisse Es nahmen 71 Kollegen (27,3 % aller befragten ärztlichen Mitglieder) an der Umfrage teil; davon hatten 28,2 % bereits Patienten mit COVID-19 betreut. Über 95 % der Teilnehmer lehnten eine präventive Anpassung der antirheumatischen Therapie im Rahmen der SARS-CoV-2-Pandemie ab. Bei ambulanten Patienten unter Immunsuppression mit nachgewiesener COVID-19-Erkrankung würden mehr als 50 % der Teilnehmer folgende Therapien aussetzen: intravenöse hoch dosierte Steroide, Cyclophosphamid, Anti-CD20-Antikörper, sowie eine BAFF-, CTLA-4-, TNF-α-Blockade. Hingegen würden nichtsteroidale Antiphlogistika, Hydroxychloroquin (HCQ), orale Steroide, Mycophenolat, IL-1-Blockade sowie Immunglobuline (Ig) von >70 % der Kollegen weiter fortgeführt. Bei stationären Patienten mit COVID-19 würden insgesamt 74,6 % der Kollegen eine COVID-19-gerichtete Therapie erwägen. Bei stabilem Verlauf unter O 2 -Therapie (Stufe I) würden am häufigsten HCQ (18,3 %), Azithromycin (16,9 %) und Ig (9,9 %) in Betracht gezogen. Bei drohendem (Stufe II) bzw. manifestem Zytokinsturm (Stufe III) würden am häufigsten Anakinra (40,8 % bei Stufe II bzw. 46,5 % bei Stufe III), Tocilizumab (26,8 % bzw. 40,8 %), Steroide (25,4 % bzw. 33,8 %) und Remdesivir (29,6 % bzw. 38,0 %) eingesetzt. Von vielen Kollegen wurde betont, dass die Therapiestrategie individuell und der klinischen Situation entsprechend angepasst werden soll. Diskussion Die Ergebnisse der Online-Umfrage sind vor dem Hintergrund einer aktuell in Deutschland niedrigen Prävalenz von COVID-19 zu sehen und spiegeln somit theoretische Überlegungen der Befragten wider. Da Kinder derzeit nicht im Fokus von prospektiven COVID-19-Studien stehen, scheint der kontinuierliche und kritische kollegiale Fachaustausch bei Therapieentscheidungen umso wichtiger zu sein
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