Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 0308-8146
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Trends in Genetics 1 (1985), S. 236-239 
    ISSN: 0168-9525
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 0896-8446
    Keywords: extraction ; solvent ; supercritical fluid
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Cell-free extracts capable of acetylene reduction and cyanide reduction have been prepared from heterocystous (Anabaena cylindrica) and non-heterocystous (Plectonema boryanum 594) blue-green algae. Extracts from Anabaena were obtained from cultures grown in blulk under aerobic conditions, while the Plectonema cultures were grown in bulk on nitrate-nitrogen, then washed free from nitrate and sparged with A/CO2 for 40 h after which time maximum nitrogenase activity was detected. The nitrogenases of both algae are similar and resemble in many respects nitrogenases from bacteria and legumes. Activity is located primarily in a 40,000xgx15 min supernatant fraction and the rate of C2H2 reduction observed is about 10 per cent of whole cell activity. ATP and a source of reducing power (Na2S2O4) are required for efficient functioning of the enzyme. ATP-dependent hydrogen evolution occurs, the extracts are cold labile and highly sensitive to oxygen and the oxygen inhibition is irreversible.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 74 (1987), S. 579-583 
    ISSN: 1432-2242
    Keywords: Felis catus ; Cat genetics ; Gene frequencies ; Colour polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The frequencies of seven mutant genes of the domestic cat have been estimated by sampling the population of greater London, specific areas of the capital and adjoining counties. An attempt was made to diversify the method of sampling by concentrating upon certain categories of cats. In addition to the usual sightings of cats in streets and open spaces, surveys were made of cats attending a veterinary clinic, those staying at a boarding cattery, those exhibited in the household pet classes at a cat show and those in rescue centres. Although there are inconsistencies, the general impression from frequencies in present and earlier observations is that the lighter phenotypes (mackerel tabby, blue dilution and orange) are favoured by human preference, as opposed to the darker phenotypes (blotched tabby, black and non-orange). Reasons are discussed for thinking that, while human preference may be a factor in the evolution of the feline polymorphism, it is not the fundamental cause.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-2145
    Keywords: Intergeneric hybridization ; Introgression ; Cross-incompatibility ; Bud pollination ; Sterility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary While Lycopersicon esculentum and Solanum lycopersicoides have been successfully hybridized, attempts at further direct gene introgression have been unsuccessful due to the presence of incompatibility barriers. A systematic study of the initial hybridization and subsequent backcrosses has identified multiple barriers to introgression. These barriers are expressed as pollen tube inhibition in the upper style and lower pistil, and failures in syngamy, zygote development, and sporogenesis. Upper style cross-incompatibility barriers were successfully avoided by bud pollinations using a stigma complementation procedure to allow pollen germination on otherwise unreceptive stigmas. The inhibition of pollen tube growth was observed in the lower pistil. A combination of environmental, plant, and genetic manipulations facilitated consistent pollen tube growth to the ovule micropyles in all crosses attempted. Failures at syngamy and early zygote formation proved to be the most difficult barriers to overcome — these were particularly severe in crosses to F1 hybrid plants. Progeny were obtained in all crossing combinations attempted except in the initial hybridization with S. lycopersicoides as the pistillate parent. Although the strong pre-zygotic barriers were overcome in this cross, further progress was restricted by post-zygotic failures. The capability to overcome pre-zygotic barriers and to excise and culture very young embryos has allowed plantlet recovery from male sterile F1 plants. Partially pollen-fertile F1 plants were recovered when relatively large F1 populations were generated from different S. lycopersicoides accessions. In general, barriers to introgression diminished with increased backcrossing, though exceptions were noted. Progeny from the second backcross to L. esculentum possessed adequate fertility to set self-seed under field conditions. Although all backcross progeny were developed from only a few F1 individuals, considerable genetic variability was recovered for fruit and vegetative characteristics. Potentially useful levels of disease resistance, particularly to Botrytis cinerea, were also recovered.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-2145
    Keywords: Self-incompatibility ; Bud pollination ; Stigma exudate ; Genetic load
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Stylar self-incompatibility barriers in L. peruvianum can be avoided if pollen germination and growth through immature pistils is promoted under specific environmental conditions approximately 2–3 days before the initiation of anthesis. Since immature stigmas lack sufficient exudate for pollen germination, the sandwiching of a thin layer of pollen germination medium between the stigma and a mineral oil layer containing pollen allows precocious pollen germination and some compatible pollen tube growth through the style. This procedure is rapid, inexpensive, applicable in the field, and makes efficient use of pollen. Consistent though low seed yields have been obtained. A high proportion of aborted seed, seedling lethals, and aberrant seedling phenotypes in selfed progeny indicate the presence of strong post-zygotic barriers to such selfing. No evidence for a reduction in the strength of the SI response with increasing pistil age was observed.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1432-2242
    Keywords: Population genetics ; Cat ecology ; Cat mutants ; Feral cats ; Ecological genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The free-living or feral cats of Portsmouth Dockyard were examined for the frequency of six mutant colour and coat genes. With the exception of one mutant, they were found to differ from the values to be expected for Southern England cat populations. The differences observed may have resulted from selection in the isolated environment (to produce a unique gene profile in terms of frequencies) or from a founder effect. If the latter, the observed frequencies could represent a relict population reflecting the frequencies of the town of Portsmouth before the dockyard was totally enclosed by a high wall. Some evidence of selection related to coat colour was found.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Zusammenfassung P. Karrer hat vor kurzem die Darstellung eines neuen Dihydrothebains durch Reduktion der Base mit Lithium-Aluminium-Hydrid beschrieben. Die Autoren können die Ergebnisse ihrer eigenen Arbeiten auf diesem Gebiet wie folgt zusammenfassen: Reduktion von Thebain vermittels Natrium in flüssigem Ammoniak ergibt eine nahezu quantitative Ausbeute an phenolischem Dihydrothebain. Diese Base ließ sich zu einem stickstoff-freien Produkt, ohne Verlust einer Seitenkette, abbauen. Es werden weiter einige Einzelheiten über das Phenyldihydrothebain mitgeteilt. Die Einwirkung von Magnesiumjodid auf Thebain in neutraler Lösung wird beschrieben.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1365-2036
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background:  Management of high-grade dysplasia in Barrett's oesophagus is controversial: surgery carries an appreciable morbidity/mortality, high-grade dysplasia may not progress to cancer and endoscopic ablation is an emerging option.Aim:  To review Barrett's oesophagus-related high-grade dysplasia management and outcome over a 10-year period.Methods:  This was a retrospective case note review of 36 patients identified from a pathology database.Results:  There were 31 men of mean age 67 years. Endoscopic surveillance identified nine. Median follow-up was 21 months. Seven patients had no further intervention because of age/comorbidity. The other 29 had repeat endoscopic biopsies, nine showing cancer (six oesophagectomized). Of the 20 remaining patients with persisting high-grade dysplasia, eight had surgery (histology showed cancer in six), seven continued endoscopic surveillance (high-grade dysplasia regressed in four) and five had ‘curative’ argon ablation. An intensive biopsy protocol was not followed in 55% of endoscopies. Prevalent cancers occurred in 44% with an annual incidence of 5% over 5 years. All cause mortality was 39% (14 of 36, eight of 14 from cancer).Conclusions:  Management of high-grade dysplasia was not uniform. Unsuspected cancer was common in high-grade dysplasia patients undergoing surgery but 13% regressed under surveillance. High-grade dysplasia patients have a high mortality but 43% did not die from cancer.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...