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1.
PAPER CURRENT
Tropospheric nitrogen dioxide column retrieval from ground-based zenith-sky DOAS observations (2015)
Publication Date: 2015-01-27
Description: Tropospheric nitrogen dioxide column retrieval from ground-based zenith-sky DOAS observations Atmospheric Measurement Techniques Discussions, 8, 935-985, 2015 Author(s): F. Tack, F. Hendrick, F. Goutail, C. Fayt, A. Merlaud, G. Pinardi, C. Hermans, J.-P. Pommereau, and M. Van Roozendael We present an algorithm for retrieving tropospheric nitrogen dioxide (NO2) vertical column densities (VCDs) from ground-based zenith-sky (ZS) measurements of scattered sunlight. The method is based on a four-step approach consisting of (1) the Differential Optical Absorption Spectroscopy (DOAS) analysis of ZS radiance spectra using a fixed reference spectrum corresponding to low NO2 absorption, (2) the determination of the residual amount in the reference spectrum using a Langley-plot-type method, (3) the removal of the stratospheric content from the daytime total measured slant column based on stratospheric VCDs measured at sunrise and sunset, and simulation of the rapid NO2 diurnal variation, (4) the retrieval of tropospheric VCDs by dividing the resulting tropospheric slant columns by appropriate air mass factors (AMFs). These steps are fully characterized and recommendations are given for each of them. The retrieval algorithm is applied on a ZS dataset acquired with a Multi-AXis (MAX-) DOAS instrument during the Cabauw (51.97° N, 4.93° E, sea level) Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI) held from the 10 June to the 21 July 2009 in the Netherlands. A median value of 7.9 × 1015 molec cm−2 is found for the retrieved tropospheric NO2 VCDs, with maxima up to 6.0 × 1016 molec cm−2. The error budget assessment indicates that the overall error σTVCD on the column values is less than 28%. In case of low tropospheric contribution, σTVCD is estimated to be around 39% and is dominated by uncertainties in the determination of the residual amount in the reference spectrum. For strong tropospheric pollution events, σTVCD drops to approximately 22% with the largest uncertainties on the determination of the stratospheric NO2 abundance and tropospheric AMFs. The tropospheric VCD amounts derived from ZS observations are compared to VCDs retrieved from off-axis and direct-sun measurements of the same MAX-DOAS instrument as well as to data from a co-located Système d'Analyse par Observations Zénithales (SAOZ) spectrometer. The retrieved tropospheric VCDs are in good agreement with the different datasets with correlation coefficients and slopes close to or larger than 0.9. The potential of the presented ZS retrieval algorithm is further demonstrated by its successful application on a 2 year dataset, acquired at the NDACC (Network for the Detection of Atmospheric Composition Change) station Observatoire de Haute Provence (OHP; Southern France).
Electronic ISSN: 1867-8610
Topics: Geosciences
2.
PAPER CURRENT
Sown flower strips in southern Sweden increase abundances of wild bees and hoverflies in the wider landscape (2015)
Publication Date: 2015-01-27
Description: Publication date: April 2015 Source:Biological Conservation, Volume 184 Author(s): Annelie M. Jönsson , Johan Ekroos , Juliana Dänhardt , Georg K.S. Andersson , Ola Olsson , Henrik G. Smith Pollinator populations have suffered severe declines in many industrialised countries due to reduced floral and nesting resources, brought on by agricultural intensification. One potential method of mitigating these effects is creating flower strips. Most previous studies have shown higher pollinator abundances in flower strips, but none have been able to demonstrate increased pollinator abundances at larger spatial scales, in the surrounding agricultural landscapes. We assessed local and landscape-wide effects of flower strips on pollinator abundances, using 18 carefully selected study landscapes in southern Sweden, distributed along independent gradients of landscape heterogeneity and farming intensity. We found that flower strips were more attractive than field borders in general to bumblebees, whereas hoverflies were only attracted to flower strips from nearby field borders. Solitary bees declined with increasing distance from flower strips, but only in complex landscapes. As one of the first studies investigating effects of flower strips on pollinators across the wider landscape, we found increased abundance of bumblebees, but not solitary bees, in field borders outside the flower strips in floristically enhanced landscapes as compared with control landscapes. However, we found that higher quality and/or larger total area of flower strips within a farm was important for both bumblebees and solitary bees. Hoverfly abundance was enhanced on farms with flower strips in simple landscapes. Our results demonstrate that flower strips with rewarding plants do not only attract pollinators locally, but in addition have the potential to increase pollinator abundances across entire landscapes, and particularly in landscapes dominated by farmland.
Print ISSN: 0006-3207
Topics: Biology
Published by Elsevier
3.
PAPER CURRENT
Impact of habitat loss on distributions of terrestrial vertebrates in a high-biodiversity region in Mexico (2015)
Publication Date: 2015-01-27
Description: Publication date: April 2015 Source:Biological Conservation, Volume 184 Author(s): Francisco Botello , Sahotra Sarkar , Víctor Sánchez-Cordero Mexico is considered a country of biological megadiversity because of its exceptional species richness and endemism. However, much of Mexico’s biodiversity is under threat due to a variety of factors, in particular, habitat loss. The Mexican legal standard (Norma Oficial Mexicana; NOM-ECOL-059-2010) uses four criteria to analyze specieś extinction risk at a national scale. However, when prioritizing areas for biodiversity conservation it is also important to incorporate knowledge of the conservation status of species at a more localized scale (regional, state, or municipal levels) for identifying possible risks associated with population declines. This paper focuses on Guerrero, which is the fourth most biologically diverse state in Mexico. The total extent of the conservation areas in Guerrero is low, amounting to 0.09% of its total area. We analyzed data for 582 terrestrial vertebrate species in Guerrero (53 amphibians, 115 reptiles, 334 birds and 80 mammals), modeling their potential distribution using a maximum entropy algorithm, and 114,555 occurrence records, and 23 predictive environmental (19 climatic and four topographical) variables. The portion of the potential distribution for each species including only remnant natural habitat was designated as its predicted distribution. The area of the predicted distribution was used to compute the fraction of natural habitat remaining for each species overlapping within decreed protected areas at the state and national levels, that is, for Guerrero and all of Mexico. Results show significant differences in the fraction of species’ predicted distribution and species’ potential distribution at different scales (state and national) and differences between the vertebrate groups analyzed. Because quantitative conservation targets are typically set for individual species, this exercise enables an analysis of the impact of the habitat lost on each species’ distribution by assessing the fraction of its predicted distribution that coincides with protected areas. We conclude that this must be part of systematic conservation planning to prioritize areas for potential conservation in Guerrero.
Print ISSN: 0006-3207
Topics: Biology
Published by Elsevier
4.
PAPER CURRENT
3α,5α-Cyclocholestan-6β-yl ethers as donors of the cholesterol moiety for the electrochemical synthesis of cholesterol glycoconjugates (2015)
Publication Date: 2015-01-27
Description: Abstract 3α,5α-Cyclocholestan-6β-yl alkyl and aryl ethers were proved to be efficient cholesteryl donors in the electrochemical synthesis of glycoconjugates. 3α,5α-Cyclocholestan-6β-ol (i-cholesterol) and its tert-butyldimethylsilyl ether can also be used for this purpose. The i-cholesterol derivatives show similar reactivities to those of previously studied 3α,5α-cyclocholestan-6β-thioethers. Beilstein J. Org. Chem. 2015, 11, 162–168. doi:10.3762/bjoc.11.16
Keywords: cholesterolelectrochemical oxidationglycosylationi-cholesteryl ethersi-steroids
Electronic ISSN: 1860-5397
Topics: Chemistry and Pharmacology
Published by Beilstein-Institut
5.
PAPER CURRENT
Structure of Bacterial Regulatory RNAs Determines Their Performance in Competition for the Chaperone Protein Hfq (2015)
Publication Date: 2015-01-27
Description: BiochemistryDOI: 10.1021/bi500741d
Print ISSN: 0006-2960
Electronic ISSN: 1520-4995
Topics: Biology , Chemistry and Pharmacology
6.
PAPER CURRENT
Countdown: Our Last, Best Hope for a Future on Earth? Alan Weisman. Little, Brown and Company (2013). xiii+513 pp., $28.00, ISBN: 978-0-316-09775-8 (Hardback) (2015)
Publication Date: 2015-01-27
Description: Publication date: April 2015 Source:Biological Conservation, Volume 184 Author(s): Eileen Crist
Print ISSN: 0006-3207
Topics: Biology
Published by Elsevier
7.
PAPER CURRENT
Synthesis, biological profiling and mechanistic studies of 4-aminoquinoline-based heterodimeric compounds with dual trypanocidal-antiplasmodial activity (2015)
Publication Date: 2015-01-27
Description: Publication date: Available online 24 January 2015 Source:Bioorganic & Medicinal Chemistry Author(s): Irene Sola , Sílvia Castellà , Elisabet Viayna , Carles Galdeano , Martin C. Taylor , Stephen Y. Gbedema , Belén Pérez , M. Victòria Clos , Deuan C. Jones , Alan H. Fairlamb , Colin W. Wright , John M. Kelly , Diego Muñoz-Torrero Dual submicromolar trypanocidal-antiplasmodial compounds have been identified by screening and chemical synthesis of 4-aminoquinoline-based heterodimeric compounds of three different structural classes. In Trypanosoma brucei, inhibition of the enzyme trypanothione reductase seems to be involved in the potent trypanocidal activity of these heterodimers, although it is probably not the main biological target. Regarding antiplasmodial activity, the heterodimers seem to share the mode of action of the antimalarial drug chloroquine, which involves inhibition of the haem detoxification process. Interestingly, all of these heterodimers display good brain permeabilities, thereby being potentially useful for late stage human African trypanosomiasis. Future optimization of these compounds should focus mainly on decreasing cytotoxicity and acetylcholinesterase inhibitory activity. Graphical abstract
Print ISSN: 0968-0896
Electronic ISSN: 1464-3391
Topics: Chemistry and Pharmacology , Medicine
Published by Elsevier
8.
PAPER CURRENT
Synthesis and biological evaluation of 4-nitroindole derivatives as 5-HT2A receptor antagonists (2015)
Publication Date: 2015-01-27
Description: Publication date: Available online 24 January 2015 Source:Bioorganic & Medicinal Chemistry Author(s): Faisal Hayat , Ambily Nath Indu Viswanath , Ae Nim Pae , Hyewhon Rhim , Woo-Kyu Park , Hea-Young Park Choo A novel series of 4-nitroindole sulfonamides containing a methyleneamino-N,N-dimethylformamidine were prepared. The binding of these compounds to 5-HT2A and 5-HT2C was evaluated, and most of the compounds showed IC50 values of less than 1μM, and exhibited high selectivity for the 5-HT2C receptor. However, little selectivity was observed in the functional assay for 5-HT6 receptors. The computational modeling studies further validated the biological results and also demonstrated a reasonable correlation between the activity of compounds and the mode of superimposition with specified pharmacophoric features. Graphical abstract
Print ISSN: 0968-0896
Electronic ISSN: 1464-3391
Topics: Chemistry and Pharmacology , Medicine
Published by Elsevier
9.
PAPER CURRENT
Folding and self-association of atTic20 in lipid membranes: implications for understanding protein transport across the inner envelope membrane of chloroplasts (2015)
Publication Date: 2015-01-27
Description: Background:The Arabidopsis thaliana protein atTic20 is a key component of the protein import machinery at the inner envelope membrane of chloroplasts. As a component of the TIC complex, it is believed to form a preprotein-conducting channel across the inner membrane.Results:We report a method for producing large amounts of recombinant atTic20 using a codon-optimized strain of E. coli coupled with an autoinduction method of protein expression. This method resulted in the recombinant protein being directed to the bacterial membrane without the addition of a bacterial targeting sequence. Using biochemical and biophysical approaches, we were able to demonstrate that atTic20 homo-oligomerizes in vitro when solubilized in detergents or reconstituted into liposomes. Furthermore, we present evidence that the extramembranous N-terminus of the mature protein displays characteristics that are consistent with it being an intrinsically disordered protein domain.Conclusion:Our work strengthens the hypothesis that atTic20 functions similarly to other small α-helical integral membrane proteins, such as Tim23, that are involved in protein transport across membranes.
Electronic ISSN: 1471-2091
Topics: Chemistry and Pharmacology
Published by BioMed Central
10.
PAPER OA
Corporate Governance in der Energiewirtschaft – zwischen Unternehmenswert und Public Value (2014)
Hochschule Darmstadt Darmstadt
Publication Date: 2015-01-27
Description: Eine verantwortungsvolle Corporate Governance soll dazu beitragen, dass einerseits das Energieunternehmen und andererseits der wesentliche Gesellschafter, die Kommune, bei der Erfüllung ihrer Ziele unterstützt werden. Wie jeder private Anteilseigner strebt die politische Führung einer Kommune einen angemessenen Einfluss auf Entscheidungen bei den Beteiligungen der kommunalen Stadtwirtschaft an. Neben dem Vertrauen in eine geeignete Geschäftsleitung und einer effektiven Unternehmensaufsicht ist besonders die Ausgestaltung des Zielsystems erfolgskritisch. Für das Zielsystem von kommunalen Energieunternehmen präsentiert der Artikel die beiden Konzepte Wertorientierte Unternehmensführung und Public Value Management. Auch wenn die Kapitalgeber bei der wertorientierten Steuerung im Vordergrund stehen, sind auch zufriedene Stakeholder die Voraussetzung für eine Erhöhung des Unternehmenswerts. Ein Wert für die Kapitalgeber wird nur geschaffen, wenn die Kunden einen hohen Nutzen wahrnehmen, die Lieferanten für ihre Produkte und Dienstleistungen wertschöpfende Erträge erwirtschaften und die Beschäftigten angemessen vergütet werden. Entsprechend ist dabei auch der Public Value zu berücksichtigen. Public Values sind Werte für die Gesellschaft, für die Bürgerinnen und Bürger einer Gebietskörperschaft oder Region. Eine Orientierung des Energieunternehmens hin zum Public Value führt zu einem ganzheitlichen Verständnis des Unternehmens als Mitglied, als aktiver und kooperierender Teil des Netzwerks Kommune. Folgende Public Values werden vorgestellt: Einbezug der Öffentlichkeit, Gesellschaftliches Engagement, Ökologische Nachhaltigkeit, Querverbund, Förderung der Gründungsregion und das regionalökonomische Netzwerk. Für diese Public Values werden jeweils anwendbare Kennzahlen zur Steuerung und Messung präsentiert. Durch die authentische Berücksichtigung des Public Value im Rahmen der Corporate Governance können sich kommunale Energieunternehmen gegenüber dem Wettbewerb, insbesondere auch den privaten Wettbewerbern differenzieren. Eine bessere Kundenbindung kann die Folge sein. Abschließend werden Ansatzpunkte für die Verbesserung der Corporate Governance im Zuge der Einführung des Public Value Ansatzes und darüber hinaus präsentiert.|An effective corporate governance intends to support the municipal energy company and the major shareholder, the community, in meeting their goals. Like any private shareholder the political leadership of a community seeks for a reasonable influence on decisions of municipal subsidiaries. In addition to the trust in an appropriate management team and an effective supervisory board particularly the design of the target system is critical for success. For the target system of municipal energy companies the article presents the concepts Value-oriented Management and Public value Management. Even if the owners are in the focus of value-based management, satisfied stakeholders are the prerequisite for an increase in corporate value. A value for the investor is only created when customers perceive high benefits, suppliers generate sufficient income for their products and services and employees receive a reasonable remuneration. In addition, the value for the public has to be considered. Public Values are values for society, for citizens of a municipality or a region. An orientation of the energy company towards public value leads to a holistic understanding of the company as a member, as an active and cooperating part of the network community. The following public values are described: citizen participation, social commitment, environmental sustainability, corporate synergies, encourage an entrepreneurial region and the regional economic network. For those public values usable key performance indicators for management and measurement are presented. Through the authentic consideration of public value in companies’ corporate governance, municipal energy companies are able to differentiate themselves from competition, especially from private competitors. A better client relationship can be achieved. Finally, aspects for the improvement of corporate governance in the context of the introduction of the public value approach and beyond are presented.
Keywords: G32 ; G34 ; G38 ; H23 ; H31 ; H70 ; H83 ; I31 ; L14 ; L21 ; L25 ; L26 ; L32 ; L94 ; L95 ; M1 ; M4 ; Q4 ; R1 ; ddc:330 ; Energiewirtschaft ; Public Value ; Gemeinwohl ; Ertragswert ; Wertorientierte Führung ; Zielsysteme ; Unternehmensstrategien ; Unternehmenssteuerung ; Corporate Governance ; Public Corporate Governance ; Unternehmensaufsicht ; Integrierte Berichterstattung
Repository Name: EconStor: OA server of the German National Library of Economics - Leibniz Information Centre for Economics
Language: deu
Type: doc-type:workingPaper