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  • 1
    Electronic Resource
    Electronic Resource
    Studies on the Maturation and Spawning of Milkfish Chanos chanos Forsskal in a Photoperiod-Controlled Room (1987)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of the World Aquaculture Society 18 (1987), S. 0 
    Details
    ISSN: 1749-7345
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Progress in propagation of milkfish has been impeded by the shortage of mature broodstock. This study was a first step toward revealing the environmental cues for the maturation of milkfish. Experiments were carried out during 1978-1985 in an indoor tank (5.2 × 4.8 × 13 m) under photoperiod control and in an outdoor tank (63 × 5.4 × 13 m). In two controlled, long-photoperiod regime experiments, 86 and 83% of the fish matured, the highest percentages yet reported. In these experiments, milkfish matured one month earlier than the normal spawning season, two months after the fish were exposed to the long daylight regime. Only 21% of the fish under a natural photoperiod regime in the outdoor tank matured. Results of the current study suggest that a change and increase in photoperiod are necessary for the onset of maturation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-7345.1987.tb01036.x
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  • 2
    Electronic Resource
    Electronic Resource
    Weed communities in intensified cereal-based cropping systems of the northern Guinea savanna (1995)
    Oxford, UK : Blackwell Publishing Ltd
    Weed research 35 (1995), S. 0 
    Details
    ISSN: 1365-3180
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: The dynamics of weed populations were ana lysed in intensified cereal-based cropping sys tems of the northern Guinea savanna in Nigeria, A total of four common weed associations were identified through cluster analysis. Five factors describing soil fertility conditions and field his tory best differentiated the weed communities according to a discriminant model. The analysis shows that maize-based cropping systems with a high frequency of cereal cropping and a low fre quency of noncereal cropping tended to be domi nated by weeds such as Commelina spp. and Kyllinga squamulata. As soil fertility declined, Vernonia spp. and Eclipta prostrata became more important. Increased frequency of noncereal crops in mixed cropping with cereals was associ ated with reduced incidence of weeds such as Leucas martinicensis, Oldenlandia corymbosa, Spermacoce verticillata, Litdwigia hyssopifolia, Celosia laxa, and,Ipomoea spp. Further diversifi cation of cereal-based systems to obtain a re duced frequency of cereals is likely to increase the incidence of Dactvloctenium aegyptium in crop fields. The information provides guidance for technology development and transfer on weed control for intensifying systems in the northern Guinea savanna of Africa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-3180.1995.tb02030.x
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  • 3
    Electronic Resource
    Electronic Resource
    Effect of orally-administered 17α-methyltestosterone on spermatogenesis in immature milkfish, Chanos chanos Forsskal (1986)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 29 (1986), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Diets containing 17α-methyltestosterone (17α-MT) were fed to milkfish, Chanos chanos, both during the spawning season (experiment 1) and after (experiment 2). The daily dosage of 17α-MT per kg of body weight was either 25 mg or 12.5 mg in experiment 1, and either 12.5 mg or 6.25 mg in experiment 2. The fish in both experiments were smaller than the minimum mature size previously reported. After 12 weeks of treatment, the treated fish had GSIs that were four times higher than the control fish in both experiments. Histologically, the testes of the control fish had only spermatogonia, in contrast to spermatozoa in the treated fish. However, no male possessed running milt. So 17α-MT induced spermatogenesis but not spermiation in the immature-sized milkfish.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1986.tb04973.x
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  • 4
    Electronic Resource
    Electronic Resource
    Effects of 17α-methyl-testosterone on spermatogenesis and spermiation in the grey mullet, Mugil cephalus L. (1985)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 26 (1985), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Diets containing 17α-Methyl-testosterone were given to grey mullet, Mugil cephalus, during the refractory period in its reproductive cycle at the dosage of 25 mg or 12.5mgkg−1 fish. Fish in experiment I were fed the diet containing methyl-testosterone every day for 55 weeks, and fish in Experiment II were fed the same diet daily for the first 10 weeks, and three times per week for the next 42 weeks. Fish were checked for the presence of sperm weekly or bi-weekly and tested for fertility during the spawning season. Terminal gonad weights and histology were compared with control groups. This study demonstrated that male mullet will mature 3 weeks or less by oral administration of 12.5 mg methyl-testosterone kg−1 fish daily. Fish can then be maintained in mature condition by feeding them methyl-testosterone at 12.5 mg kg−1 three times per week.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1985.tb04243.x
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  • 5
    Electronic Resource
    Electronic Resource
    Beeinflussung der Spin-Bahn-Aufspaltungskonstanten durch die Liganden in stark gebundenen Oktaederkomplexen (1966)
    Springer
    The European physical journal 190 (1966), S. 135-141 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The effect of the octahedral ligand field on the spin-orbit splitting factor of at 2g -electron in strongly bound complexes is considered including the screening by the ligands.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01327139
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  • 6
    Electronic Resource
    Electronic Resource
    Messung der differentiellen magnetischen Suszeptibilität von HoCl3, Ho(Y)Cl3 und Ho(La)Cl3 bei Heliumtemperaturen (1968)
    Springer
    The European physical journal 217 (1968), S. 373-385 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The differential magnetic susceptibility X=X′-iX″ of HoCl3, Ho(Y)Cl3, and Ho(La)Cl3 has been measured with a mutual inductance bridge with frequencies from 5.3 c/s to 5.12 kc/s at temperatures between 1.1 and 4.2 °K, and in constant magnetic fields up to 3 kOe. — In monoclinic HoCl3 a magnetic transition has been observed atT=2.15 °K (maximum of X″). No transition occurs for 0.5 and 5% Ho3+ in isomorphic YCl3. — The results for nominal concentrations of 1, 2, and 5% Ho3+ in hexagonal LaCl3 indicate, that there is a considerable precipitation of monoclinic HoCl3 during crystal growth. Relaxation measurements on Ho3+ in hexagonal sites are interpreted in terms of a phonon-bottleneck in the temperature region 1.1 °K≦T≦2.00K with a hot-phonon equilibration time of about 0.2 μs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01391478
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  • 7
    Electronic Resource
    Electronic Resource
    Determination of semi-muonic branching ratios and fragmentation functions of heavy quarks ine + e − annihilation at $$\langle \sqrt s \rangle $$ =34.6 GeV (1987)
    Springer
    The European physical journal 33 (1987), S. 339-349 
    Details
    ISSN: 1434-6052
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Muon inclusive multihadronic final states ine + e − annihilation at $$\langle \sqrt s \rangle $$ =34.6 GeV, collected by the JADE detector at PETRA, have been analysed in terms of the semi-muonic branching ratios and fragmentation functions of heavy quarks. Defining the fragmentation variable, ζ, as $$z = \frac{{\left( {E + p_\parallel } \right)_{hadron} }}{{\left( {E + p} \right)_{quark} }}$$ we find 〈z c 〉=(77±3±5)% and 〈z b 〉=(86±4±5)%. The corresponding semi-muonic branching ratios are measured to be BR(c→μv μ X)=7.8±1.5±2)% and BR (b→μv μ X)=(11.7±1.6±1.5)%. Defining ζ as $$x_E = \frac{{E_{hadron} }}{{E_{beam} }}$$ we observe an expected softening effect in the fragmentation due mainly to gluon emission, but find that this definition leads to semi-muonic branching ratiomeasurements which are strongly affected by uncertainties in the fragmentation process and the WCD calculation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01552539
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  • 8
    Electronic Resource
    Electronic Resource
    Genetic variability in host plant adaptation of the green peach aphid, Myzus persicae (1985)
    Springer
    Entomologia experimentalis et applicata 38 (1985), S. 49-56 
    Details
    ISSN: 1570-7458
    Keywords: Homoptera ; Aphididae ; Myzus persicae ; Solanum tuberosum ; Beta vulgaris ; genetic variability ; host plant adaptation ; preference ; polyphagy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Grüne Pfirsichblattlaus Myzus persicae (Sulz.) lebt polyphag an über 400 Pflanzenarten in mehr als 50 Pflanzenfamilien. Ein breites Nahrungsspektrum einer Art ergibt sich jedoch aus der phänotypischen Plastizität des Individuums oder einer Klonlinie und der genetischen Variabilität der Population. Felpopulationen der Grünen Pfirsichblattlaus wurden auf ihre genetische Variabilität bezüglich der Wirtspflanzenanpassung an Rübe und Kartoffel untersucht. Eine Analyse von mehr als 1 000 Klonen, die über die Jahre 1980, 1981 und 1982 im Rheinland gesammelt wurden, lassen eine breite Variabilität in der Wirtspflanzenanpassung der Population erkennen. Beide Merkmale scheinen unabhängig voneinander vererbt zu werden und zeigen keine Beziehung zum Wirtswahlverhalten adult apterer Läuse der entsprechenden Klone. Die Art M. persicae kann daher charakterisiert werden als eine polyphage Insektenart mit einer breiten genetischen Variabilität und einer grossen phänotypischen Plastizität. Eine generelle Differenzierung von Herbivoren in Generalisten und Spezialisten vernachlässigt die genetische Komponente in der komplexen Beziehung zwischen Insekten un ihren Wirtspflanzen.
    Notes: Abstract The green peach aphid, Myzus persicae (Sulz.), is polyphagous on over 400 plant species in more than 50 families. Phenotypic plasticity of individuals and genetic variability in the population presumably contribute to this polyphagy. The genetic variability in field populations of M. persicae was assessed with respect to their adaptation to sugar beets and potatoes. An analysis of more than 1 000 clones, sampled during 1980, 1981 and 1982 from different host plants in the field, revealed a wide genetic variability in host plant adaptation to sugar beets as well as to potatoes. Both traits seem to be inherited independently from each other and do not correlate with clone-specific host plant preference of apterous adults. The aphid M. persicae can be characterized as a polyphagous insect species with a wide, continuously distributed variability and a broad phenotypic plasticity. A general differentiation of herbivorous species into generalists and specialists tends to ignore the genetic component in the complex of insect-plant relationships.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00163352
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  • 9
    Electronic Resource
    Electronic Resource
    Microperforation of plant tissue with a UV laser microbeam and injection of DNA into cells (1988)
    Springer
    Naturwissenschaften 75 (1988), S. 35-36 
    Details
    ISSN: 1432-1904
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00367437
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  • 10
    Electronic Resource
    Electronic Resource
    Synchronization of cells from higher plants (1985)
    Springer
    Naturwissenschaften 72 (1985), S. 438-439 
    Details
    ISSN: 1432-1904
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00404893
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