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1

Digitale Medien

Regulated flushing in a gravel-bed river for channel habitat maintenance: A Trinity River fisheries case study (1987)

Nelson, R. Wayne ; Dwyer, John R. ; Greenberg, Wendy E.

Springer

Environmental management 11 (1987), S. 479-493

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ISSN: 1432-1009

Schlagwort(e): Flushing ; Scouring ; Channel Maintenance ; Fisheries ; Trinity River

Quelle: Springer Online Journal Archives 1860-2000

Thema: Energietechnik

Notizen: Abstract The operation of Trinity and Lewiston Dams on the Trinity River in northern California in the United States, combined with severe watershed erosion, has jeopardized the existence of prime salmonid fisheries. Extreme streamflow depletion and stream sedimentation below Lewiston have resulted in heavy accumulation of coarse sediment on riffle gravel and filling of streambed pools, causing the destruction of spawning, nursery, and overwintering habitat for prized chinook salmon (Salmo gairdnerii) and steelhead trout (Oncorhynchus tschawytscha). Proposals to restore and maintain the degraded habitat include controlled one-time remedial peak flows or annual maintenance peak flows designed to flush the spawning gravel and scour the banks, deltas, and pools. The criteria for effective channel restoration or maintenance by streambed flushing and scouring are examined here, as well as the mechanics involved. The liabilities of releasing mammoth scouring-flushing flows approximating the magnitude that preceded reservoir construction make this option unviable. The resulting damage to fish habitat established under the postproject streamflow regime, as well as damage to human settlements in the floodplain, would be unacceptable, as would the opportunity costs to hydroelectric and irrigation water users. The technical feasibility of annual maintenance flushing flows depends upon associated mechanical and structural measures, particularly instream maintenance dredging of deep pools and construction of a sediment control dam on a tributary where watershed erosion is extreme. The cost effectiveness of a sediment dam with a limited useful economic life, combined with perpetual maintenance dredging, is questionable.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF01867656

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2

Digitale Medien

Age, growth and reproductive biology of the silky shark, Carcharhinus falciformis, and the scalloped hammerhead, Sphyrna lewini, from the northwestern Gulf of Mexico (1987)

Branstetter, Steven

Springer

Environmental biology of fishes 19 (1987), S. 161-173

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ISSN: 1573-5133

Schlagwort(e): Chondrichthyes ; Elasmobranchs ; Fisheries ; Ageing methods ; Growth rates ; Gestation periods ; Maturity ; Vertebral bands ; Weight-length relationships ; Life histories

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie

Notizen: Synopsis The silky shark, Carcharhinus falciformis, and scalloped hammerhead, Sphyrna lewini, represent 〉80% of the shark by-catch of the winter swordfish/tuna longline fishery of the northwestern Gulf of Mexico. This catch represents a potential supplemental fishery, yet little is known of the life histories of the two species. This report relates reproductive biology data to age and growth estimates for 135 C. falciformis and 78 S. lewini. Unlike other regional populations, C. falciformis in the Gulf of Mexico may have a seasonal 12 month gestation period. Males mature at 210–220 cm TL (6–7 yr); females at 〉225 cm TL (7–9 yr). Application of age at length data for combined sexes produced von Bertalanffy growth model parameter estimates of L∞ = 291 cm TL, K = 0.153, t0 = −2.2 yr. Adult male S. lewini outnumbered adult females in catches because of differences in the distributions of the sexually segregated population. Males mature at 180 cm TL (10 yr); females at 250 cm TL (15 yr). von Bertalanffy parameter estimates for combined sexes of this species were L∞ = 329 cm TL, K = 0.073, to = −2.2 yr.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00005346

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3

Digitale Medien

The need for conservation and management of Philippine coral reefs (1988)

Rubec, Peter J.

Springer

Environmental biology of fishes 23 (1988), S. 141-154

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ISSN: 1573-5133

Schlagwort(e): Cyanide ; Diversity ; Development ; Ecology ; Environment ; Fisheries ; Pollution

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie

Notizen: Synopsis The biological diversity and productivity of Philippine coral reefs are threatened by siltation, destructive fishing methods, coral and shell collecting and overfishing. Destructive fishing includes: the widespread, illegal use of explosives; poisons such as sodium cyanide; muro-ami and kayakas fishing; and trawling. The recent decline in catch rates threatens the livelihood of 700 000 near-shore subsistence fishermen who catch 55% of the total landings. The new government under Corazon Aquino wishes to protect the marine environment through the creation of a viable marine conservation management plan, enforcement of existing laws and through cooperation between government, non-government and international agencies to provide education and research. The Department of Agriculture, which has the authority for fisheries, has designated the International Marinelife Alliance as the lead non-government agency involved with fund raising, net-training and finding alternatives to destructive fishing methods.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00000745

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4

Digitale Medien

Masthead (1985)

New York, NY : Wiley-Blackwell

Helvetica Chimica Acta 68 (1985)

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ISSN: 0018-019X

Schlagwort(e): Chemistry ; Organic Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/hlca.19850680101

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5

Digitale Medien

Inverted Hyperconjugation in Symmetrical 1,4-DihalocubanesPart IV of ‘The Equivalent Bond Orbital Model Revisited’ (Part III: [1]), and Part 50 of ‘Small and Medium Rings’ (Part 49: [1]). (1985)

Honegger, Evi ; Heilbronner, Edgar ; Urbanek, Thomas ; [weitere]

New York, NY : Wiley-Blackwell

Helvetica Chimica Acta 68 (1985), S. 23-38

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ISSN: 0018-019X

Schlagwort(e): Chemistry ; Organic Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Notizen: The σ-orbital manifold of cubane 1, as suggested by its PE spectrum, is divided into two sets separated by a 3 eV gap extending from ∼ -10.5 eV to ∼ -13.5 eV. Halogen substituents with np AO basis energies falling into this gap (e.g. Cl or Br) will, therefore, hyperconjugate appreciably with both sets. Interaction with the lower-lying set will lead to the usual destabilization (‘normal’ hyperconjugation), whereas interaction with the set above will necessarily lead to a ‘stabilization’ (‘inverted’ hyperconjugation). As a result the lone-pair ionization energies of Cl or Br substituted cubanes (derived from PE spectra) are much larger than naively expected for an alkyl halide containing as much as 8 C-atoms. In particular no significant shift of the eg-1 lone-pair bands in the PE spectra of 1,4-dichloro- and 1,4-dibromocubane can be detected with respect to the first ionization energies of the free atoms Cl and Br, or of HCl and HBr.

Zusätzliches Material: 7 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/hlca.19850680104

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6

Digitale Medien

Sesquiterpenoids of the Sponge Dysidea fragilis of the North-Brittany SeaPresented by F.P. as a part of a lecture at the University of Innsbruck on March 15th, 1984. (1985)

Guella, Graziano ; Guerriero, Antonio ; Pietra, Francesco

New York, NY : Wiley-Blackwell

Helvetica Chimica Acta 68 (1985), S. 39-48

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ISSN: 0018-019X

Schlagwort(e): Chemistry ; Organic Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Notizen: The title sponge is shown to contain eight new sesquiterpenoids for which a common, unusual biogenetic origin is postulated. The compounds are shown to be: (-)-(1R*,4R*)-3-(3′-furyl)methyl-2-p-menthen-7-yl acetate ((-)-8b); two diols separated as the monoacetates (-)-(1S*,4R*)-3-(3′-furyl)methyl-l-hydroxy-2-p-menthen-7-yl acetate ((-)-13a) and the (-)-(1R*,4R*)-epimer (-)-13b, the two C(4)-epimeric 4-ethoxy-3-(1′(7′),2′-p-menthadien-3′-yl)methyl-2-buten-4-olides ((+)-14a and (-)-14b), (-)-3-(3′-furyl)methyl-7-nor-2-p-menthen-l-one ((-)-11), (-)-(3Z)-1-(3′-furyl)-4,8-dimethylnona-3, 7-dien-2-yl acetate ((-)-17), and (+)-3-(5′,7′-seco-2′(10′)-pinen-7′-yl)methylfuran ((+)-15).

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/hlca.19850680105

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7

Digitale Medien

Melanotropin Receptors I. Synthesis and Biological Activity of Nα-(5-Bromovaleryl)-Nα-deacetyl-α-melanotropinParts of this report have appeared as a thesis [1]. Nomenclature and abbreviations [2]. Additional abbreviations: MSH = melanophore stimulating hormone (melanotropin), DCC = N, N′-dicyclohexylcarbodiimide, DCU = N, N′-dicyclohexylurea, DMF = dimethylformamide, HOBt = 1-hydroxybenzotriazole, Boc = tert-butoxycarbonyl, OBut = tert-butoxy, Msoc = 2-(methylsulfonyl)ethoxycarbonyl, Np = 4-nitrophenyl, Z = benzyloxycarbonyl, TFA = trifluoroacetic acid. Chiral amino acids are in their L-configuration. Culture media see Experimental.Dedicated to Dr. Nitya Anand, Director of the Central Drug Research Institute, Lucknow, India, on the occasion of his 60th birthday (1985)

Wunderlin, Rudolf ; Minakakis, Panagiota ; Tun-Kyi, Aung ; [weitere]

New York, NY : Wiley-Blackwell

Helvetica Chimica Acta 68 (1985), S. 1-11

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ISSN: 0018-019X

Schlagwort(e): Chemistry ; Organic Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Notizen: Chemical synthesis and biological activities of a new α-melanotropin derivative are described. Nα-(5-Bromovaleryl)-Nα-deacetyl-α-melanotropin contains the 5-bromopentanoyl group as a chemical ‘handle’ in place of the acetyl group of the natural hormone. The synthesis involved a new protected intermediate which allowed the selective deprotection of either the Nα or Nα amino group. The title compound reacted with sodium thiosulfate to give Nα-deacetyl-Nα-(5-(sulfothio)valeryl)-α-melanotropin, a key intermediate for the preparation of tobaccomosaic virus/α-melanotropin disulfide conjugates. As a basis for the study of the conjugates, biological activities of the title compound on Cloudman S-91 mouse melanoma cell cultures (tyrosinase stimulation, binding, and cyclic AMP accumulation) were determined. They proved to be quite similar to the corresponding α-melanotropin activities. Differences in bindings may be explained by stronger hydrophobic interaction of the new derivative with the lipid phase of the target cell membranes.

Zusätzliches Material: 9 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/hlca.19850680102

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8

Digitale Medien

Bond Angles in Lactones and Lactams (1985)

Nørskov-Lauritsen, Leif ; Bürgi, Hans-Beat ; Hofmann, Peter ; [weitere]

New York, NY : Wiley-Blackwell

Helvetica Chimica Acta 68 (1985), S. 76-82

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ISSN: 0018-019X

Schlagwort(e): Chemistry ; Organic Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Notizen: The carbonyl group in lactones and, to a lesser extent, in lactams tends to show a C—C=O angle that is larger than the O—C=O or N—C=O angle, the difference increasing in magnitude as the ring size decreases. The observed trend provides information on ratios of force constants characterising the flexibility of the s-cis-ester group and may be interpreted in terms of incipient chemical reaction to -O—(CH2)n—C≡O+. Molecular orbital calculations (MINDO/3, MNDO, EH) for model compounds provide an electronic interpretation of this angle difference in terms of an anomeric interaction between the p-type lone pair on the carbonyl O-atom and the antibonding C-O or C-N orbital.

Zusätzliches Material: 3 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/hlca.19850680110

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9

Digitale Medien

Cyclic Octa- and Decapeptides as Ionophores for Magnesium (1985)

Behm, Felix ; Ammann, Daniel ; Simon, Wilhelm ; [weitere]

New York, NY : Wiley-Blackwell

Helvetica Chimica Acta 68 (1985), S. 110-118

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ISSN: 0018-019X

Schlagwort(e): Chemistry ; Organic Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Notizen: Cyclic octa- and decapeptides have been prepared, and their ion selectivity in solvent polymeric membranes was studied. Cyclo(-LPro-DLeu-)5 behaves as an ionophore which selects Mg2+ over Ca2+ by a factor of 100. Cyclo(LPro-LLeu)5 induces selectivity in membranes for Mg2+ over Li+, Na+ and K+ by a factor of 400, 200 and 10, respectively, while selectivity of Mg2+ over Ca2+ is poor. Some evidence is presented which indicates that certain ionophores exhibit high selectivity for monovalent magnesium complexes.

Zusätzliches Material: 6 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/hlca.19850680114

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10

Digitale Medien

Stereoselective Double Functionalization of Iron-Carbonyl Complexes of 5,6,7,8-Tetramethylidenebicyclo[2.2.2]oct-2-ene. Crystal Structure and Absolute Configuration of (-)-trans-μ-[(2S,5R,7S)-C,5,6,C-η:C,7,8,C-η-(6,7,8-trimethylidene-5-((Z)-2-oxopropylidene)-2-bicyclo[2.2.2]octyl acetate)]-bis(tricarbonyliron) (1985)

Tagliaferri, Enrico ; Campiche, Philippe ; Roulet, Raymond ; [weitere]

New York, NY : Wiley-Blackwell

Helvetica Chimica Acta 68 (1985), S. 126-134

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ISSN: 0018-019X

Schlagwort(e): Chemistry ; Organic Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Notizen: The Friedel-Crafts monoacylation of trans-η-[(1RS,2RS,4SR,5SR,6RS,7SR,8SR)-C,5,6,C-η:C,7,8,C-η-(5,6,7,8-tetramethylidene-2-bicyclo[2.2.2]octyl acetate)]-bis(tricarbonyliron) ((±)-5) is highly stereoselective and yields trans-η-[(1RS,2RS,4RS,5SR,6RS,7RS,8SR)-C,6-η,oxo-σ:C,7,8,C-η-(6,7,8-trimethylidene-5-((Z)-2-oxopropylidene)-2-bicyclo[2.2.2]octyl acetate)]-bis(tricarbonyliron) ((±)-8) which equilibrates with the trans-η-[(1RS,2RS,4RS,5SR,6RS,7RS,8SR)-C,5,6,C-η:C,7,8,C-η-(6,7,8-trimethylidene-5-((Z)-2-oxopropylidene)-2-bicyclo[2.2.2]octyl acetate)]-bis(tricarbonyliron) ((±)-9) on heating. Optically pure (-)-9 has been prepared from the corresponding optically pure alcohol (+)-4. The structure and absolute configuration of (-)-9 was established by single-crystal X-ray diffraction.

Zusätzliches Material: 4 Tab.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/hlca.19850680116

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