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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Transportation 22 (1995), S. 295-323 
    ISSN: 1572-9435
    Keywords: densities ; development ; environment ; externalities ; land-use ; planning
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying
    Notes: Abstract There are clear signs of a shift in the UK transport policy in response to concerns about the environmental impacts of road transport and anxieties about the implications of the projected future growth in demand. Much of the framework of UK transport policy is now determined at the overall European Union level. To date most European legislation and policy proposals have been concerned with reducing the specific externalities associated with the transport sector, with none of the measures involved likely to have more than a marginal impact on the growth in demand. The emerging research evidence suggests however that the private costs of car use in Europe may fall substantially short of its total social costs and there is an important emerging policy debate about how this gap might be closed. The UK has introduced a policy package designed to reduce the growth of car travel and its environmental impact, within which land-use planning measures feature prominently. The land-use policies, which to some extent represent a reassertion of many traditional UK planning policies, include: an emphasis on focussing new development in urban areas, increasing residential densities, strengthening the role of existing centres and improving provision for walking and cycling. A number of factors will constrain the effectiveness of the package in practice. There are also concerns about its impact on key environmental objectives, including air quality. There are important questions too about the welfare effects of increasing densities and about the wider impacts of the package on economic efficiency.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1573-1561
    Keywords: Picea pungens ; Picea glauca ; feeding deterrent ; spruce budworm ; Choristoneura fumiferana (Clem.) ; Lepidoptera ; Tortricidae ; pungenin ; protection of OH groups ; glucoside ; phenolic glucoside
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Pungenin was synthesized from 3,4-dihydroxyacetophenone by a short sequence involving manipulation of protecting groups on the 3 and 4 hydroxyl functions. Bioassays indicated that the glucoside is a modest feeding deterrent for sixth-instar spruce budworm larvae, but it does not appear to retard the development of small larvae or lead to increased mortality.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of assisted reproduction and genetics 15 (1998), S. 594-598 
    ISSN: 1573-7330
    Keywords: blastocyst ; development ; fertilization ; intracytoplasmic sperm injection ; in vitro fertilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose: To examine the blastocyst formation rates of day-2 fertilized oocytes. Methods: A retrospective study of the outcomes/blastocyst formation of day-2 fertilized oocytes was undertaken. Results: Fertilization rates of day-1 and -2 oocytes by intracytoplasmic sperm injection were similar. The development frequencies to four cells were similar. However, the blastulation rates were significantly lower from the day-2 fertilized eggs. The fertilization rates from day-2 conventional in vitro fertilization reinsemination were lower than the fertilization rates of day-1 oocytes. The blastulation rates from day-2 fertilized eggs were also lower than the rates from day-1 fertilized eggs in the in vitro fertilization group. Conclusions: Fertilization is not a good indicator to predict the viability of fertilized oocytes. Day-2 fertilized oocytes had significantly lower blastocyst formation rates than the rates from day-1 fertilized oocytes.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of assisted reproduction and genetics 11 (1994), S. 303-307 
    ISSN: 1573-7330
    Keywords: mouse ; embryo ; culture medium ; development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose Our purpose was to find a medium to enhance mouse zygote development and, hopefully, to apply the results to a coculture system and to enhance the ART pregnancy rate. Design The study was designed to compare different media's support of mouse zygote development with/without serum supplement. The outcome measure was the percentage of mouse zygotes/embryos that developed to the expanded blastocyst and hatchout stage. Results (1) Using human tubal fluid (HTF), one-cell zygotes had a 34.6±5.2% (mean±standard deviation) development rate, and two-cell embryos a 86.5±3.2% development rate. (2) Minimum essential medium alpha (MEM) showed the best results (52.2±14.5%) among Ham's F-10 (19.1±6.3%), HTF (26.8±8.2%), NCTC-135 (38.8±12.6%), MEM with nuclei acid (24.6±10.0%), and Dulbecco's modified Eagle medium (28.0±20.2%). (3) With the serum supplement, there was no significant difference among Ham's F-10 (21.5±23.7), HTF (29.3±10.4%), NCTC-135 (36.5±6.2%), and MEM (38.8±17.9%). Conclusion MEM is the best medium among the six media examined. Preliminary study showed that MEM gave a good clinical pregnancy rate (29%).
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1573-1561
    Keywords: Trichothecenes ; sesquiterpines ; Fusarium sporotrichioides ; fungal toxins ; insecticidal activity ; fungal pathogen ; Paecilomyces farinosus ; spruce budworm ; Choristoneura fumiferana ; Lepidoptera ; Tortricidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Trichothecene mycotoxins were produced byFusarium sporotrichioides DAOM 197255 isolated from a spruce budworm cadaver. An extract from the culture filtrate containing these metabolites was toxic to budworm when ingested at concentrations as low as 10 ppm in diet, and survivors were predisposed to infection with a fungal entomopathogen. The possible role of these metabolites in the balsam fir-spruce budworm habitat is discussed.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1573-1561
    Keywords: Enniatins ; cyclodepsipeptides ; Fusarium avenaceum ; Abies balsamea ; balsam fir ; Choristoneura fumiferana ; Lepidoptera ; Tortricidae ; spruce budworm ; insecticide ; toxin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Material extracted from hyphae ofFusarium avenaceum, isolated from foliage of balsam fir,Abies balsamea, was toxic to spruce budworm larvae when incorporated into insect diet. The major insecticidal component of the toxic fraction was identified by chemical and spectroscopic methods as enniatin complex, rich in enniatin A/A1. Possible ecological implications of these observations are considered.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,3-Dipolar Cycloadditions, 82. Kinetics and Mechanism of the Cycloadditions of C-(2,2′-Biphenylylen)-Nα-(4-chlorphenyl)-Nβ-cyan-azomethinimine ImineThe cycloaddition rates of the title compound to 22 dipolarophiles in chlorobenzene was measured photometrically; the k2 values range over more than 4 powers of ten. Conjugation as well as electron-attracting and -releasing substitution in the ethylenic dipolarophile increase the activity. The azomethine imine 1 belongs to those 1,3-dipoles for which both HOMO-LUMO interactions with the dipolarophile influence the energy of the transition state to a comparable extent. The activity scale of dipolarophiles is compared with those which were measured versus N-methyl-C-phenylnitrone, diphenylnitrilimine and benzonitrile oxide. 1,3-Dipoles of the allyl type, in contrast to the ones of the propargyl-allenyl type, react especially fast with acetylenic carboxylic esters. - The activation entropies of the cycloadditions of 1 amount to -29 to -35 e. u. - With increasing solvent polarity the k2 values of the reaction of 1 with dimethyl acetylenedicarboxylate is reduced 6 fold. The dipole moments of reactants and adduct suggest a decrease of charge separation in the activation process of the concerted cycloaddition.
    Notes: Die Geschwindigkeit der Cycloadditionen der Titelverbindung an 22 Dipolarophile wurde in Chlorbenzol photometrisch gemessen; die k2-Werte überstreichen mehr als 4 Zehnerpotenzen. Konjugation sowie elektronen-anziehende oder -liefernde Substitution im ethylenischen Dipolarophil erhöhen die Aktivität. Das Azomethin-imin 1 gehört zu den 1,3-Dipolen, bei denen beide HOMO-LUMO-Wechselwirkungen in gleicher Größenordnung die Energie des Übergangszustandes der Cycloaddition beeinflussen. Die Aktivitätsskala der Dipolarophile wird mit denen, die gegenüber N-Methyl-C-phenylnitron, Diphenylnitrilimin und Benzonitriloxid gemessen wurden, verglichen. 1,3-Dipole vom Allyl-Typ reagieren im Gegensatz zu denen des Propargyl-Allenyl-Typs rascher mit Acetylencarbonestern als mit Ethylencarbonestern. - Aktivierungsentropien von -29 bis -35 Clausius wurden gemessen. - Mit steigender Solvenspolarität fällt der k2-Wert der Cycloaddition von 1 an Acetylendicarbonester um den Faktor 6; die Dipolmomente von Reaktanten und Addukt lassen eine Verminderung der Ladungstrennung im Aktivierungsvorgang der konzertierten Cycloaddition erwarten.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Existence of a Silaolefin: Synthesis and Crystal Structures of Wittig and Diels-Alder Products in Reactions of Lithiated (Fluorosilyl)diazasilacyclopentenes with Benzaldehyde and MethacroleinLithium salts of 1,2-diaza-3-sila-5-cyclopentenes react with fluorosilanes and aminofluorosilanes to give 4-(fluorosilyl)-substituted compounds 1 - 4. By reaction with tert-butyllithium 1 - 4 themselves form lithium salts 5 - 8, which react with fluorosilanes in a second substitution giving 9 and 10.5 and 7 undergo a Wittig-type reaction with benzaldehyde to form the benzylidene derivative 11. Spirocyclic Diels-Alder adducts (12, 13) are obtained from the reaction of 5 and 6 with 2-methyl-2-propenal. The propenylidene derivative 14 is formed as a by product. With excess 2-methyl-2-propenal, 12 reacts as a dienophile giving the oligocyclic Diels-Alder adducts 15 and 16. The crystal structures of 11 and 15 are reported.
    Notes: Lithiumsalze der 1,2-Diaza-3-sila-5-cyclopentene reagieren mit Fluorsilanen und Aminofluorsilanen zu den 4-(Fluorsilyl)-substituierten Verbindungen 1 - 4. In Reaktion mit tert-Butyllithium bilden 1 - 4 erneut Lithiumsalze (5 - 8), die mit Fluorsilanen unter Zweitsubstitution zu 9 und 10 reagieren. In Wittig-analoger Reaktion reagieren 5 und 7 mit Benzaldehyd zum Benzyliden-Derivat 11. Spirocyclische Diels-Alder-Addukte (12, 13) werden aus 5 und 6 mit 2-Methyl-2-propenal erhalten. Als Nebenprodukt entsteht das Propenyliden-Derivat 14. Mit überschüssigem Dien (2-Methyl-2-propenal) reagiert 12 als Dienophil zu den oligocyclischen Diels-Alder-Addukten 15 und 16. Kristallstrukturen von 11 und 15 werden mitgeteilt.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 116 (1983), S. 290-298 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Cyclic Silylhydrazines - Crystal Structure of a Five-membered Cross Dimerisation ProductN,N-Bis(fluorosilyl)amines (1 - 3) react with dilithiated hydrazines to give four- and five-membered silylhydrazine rings (4 - 8). The isomerisation of a 3-(tert-butylamino)-1,3-diaza-2,4-disilacyclobutane (8) to a 1,2,4-triaza-3,5-disilacyclopentane (9) has been demonstrated. Lithium salts of silylhydrazines react with fluorosilanes to give substitution products (10 - 15). Dilithiated hydrazine reacts with Me2SiF2 yielding N(SiFMe2)3 (16). The formation of isomeric N-(fluorosilyl)-N,N′-bis(trimethylsilyl)- and N′-(fluorosilyl)-N,N-bis(trimethylsilyl)hydrazines has been accomplished via ring-closure reactions (17 - 19) and confirmed by the crystal structure determination of a five-membered ring cross dimer (19). The ten-membered bicyclic ring system (22) is obtained by the reaction of (14) with dilithiated hydrazine.
    Notes: N,N-Bis(fluorsilyl)amine (1 - 3) reagieren mit dilithiierten Hydrazinen zu vier- und fünfgliedrigen Silylhydrazinringen (4 - 8). Präparativ gelang der Nachweis der Isomerisierung eines 3-(tert-Butylamino)-1,3-diaza-2,4-disilacyclobutans (8) zum 1,2,4-Triaza-3,5-disilacyclopentan (9). Lithiumsalze von Silylhydrazinen reagieren mit Fluorsilanen unter Substitution (10 - 15). Dilithiiertes Hydrazin reagiert mit Me2SiF2 zu N(SiFMe2)3 (16). Die Bildung von isomeren N-(Fluorsilyl)-N,N′-bis(trimethylsilyl)- und N′-Fluorsilyl-N,N-bis(trimethylsilyl)hydrazinen wird durch Ringschlußreaktionen (17 - 19) nachgewiesen und durch die Kristallstrukturuntersuchung eines Kreuz-Dimeren-Fünfrings belegt (19). Der zehngliedrige Bicyclus 22 entsteht in der Reaktion des N,N′-Bis(fluordimethylsilyl)-N,N′-bis(trimethylsilyl)hydrazins(14) mit dilithiiertem Hydrazin.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 3150-3157 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Addition Reactions of 1,1-Dicyano-2,2-bis(trifluoromethyl)etheneBy the reaction of the title compound (CF3)2C=C(CN)2 with PCl5 the (phosphoranyliden-amino)ethene 1 is obtained. The phosphorane 1 reacts with Me3SiNMe2 to form 2. WCl6 and MoCl5 react with (CF3)2C=C(CN)2 to give the acyclic nitrenes 3 and 4. The X-ray structure analysis of 3a, an acetonitrile adduct of 3, is reported.
    Notes: Die Titelverbindung (CF3)2C=C(CN)2 reagiert mit PCl5 zu dem (Phosphoranylidenamino)-ethen 1. Daraus entsteht 2 durch Reaktion mit Me3SiNMe2. Umsetzungen von (CF3)2C=C(CN)2 mit WCl6 und MoCl5 ergeben die acyclischen Nitrenkomplexe 3 und 4. Von 3a, einem Acetonitriladdukt von 3, wird eine Röntgenstrukturanalyse mitgeteilt.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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