Library

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    Baltimore : Periodicals Archive Online (PAO)
    Human Biology. 51:1 (1979:Feb.) 23 
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 33 (1977), S. 992-996 
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: The rare-earth metal oxides are known to exhibit several phases which can be either stoichiometric or nonstoichiometric. One such phase which has been recently found to exist in thin-film form corresponds to the monoxide phase RO. The oxygen content in this phase, however, has been found to vary such that the phase actually has the stoichiometry ROx with 1 〈 x 〈 2. The present paper deals with electron diffraction studies of the SRO → LRO transition in the nonstoichiometric ROx phase. This transition commences as a result of the creation of oxygen vacancies in the as-grown thin-film phase, when this phase is pulse annealed with an electron beam in the electron microscope, the annealing temperature being about 500°C. The short-range ordered version is manifested by the appearance of curious diffuse streaks on the diffraction patterns. The diffuse intensity distribution has been found to be situated on a complicated surface (rhombic dodecahedron) in the reciprocal space of the initial f.c.c. phase with a = 5.09 ± 0.05 Å and 5.37 ± 0.05 Å for erbium and dysprosium oxides respectively. On further pulse annealing at a higher temperature ( ̃900°C), the short-range ordered version yields to give rise to a long-range ordered superlattice phase which corresponds to the bulk-like b.c.c. phase with a = 10.41 ± 0.05 Å and 10.18 ± 0.05 Å for erbium and dysprosium oxides respectively. The SRO → LRO transition has also been analysed in terms of the stoichiometric variations resulting from the pulse annealing.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Plant Science 52 (1987), S. 237-242 
    ISSN: 0168-9452
    Keywords: Lycopersicon ; embryo culture ; organogenesis ; propagation ; somatic embryogenesis ; tissue culture ; tomato
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Planta 169 (1986), S. 245-250 
    ISSN: 1432-2048
    Keywords: Acacia ; Nucellus ; Ovule ; Pollen tube arrest ; Sell-incompatibility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In self-incompatible Acacia retinodes Schldl. var. uncifolia J.M. Black there is no inhibition of self pollen tubes before entry into the ovule, but the frequency of fertilized embryo sacs observed after self pollination is only 0.09–0.24 of that observed after outcrossing. Fluorescence- and light-microscope studies of sectioned, squashed or cleared whole ovules indicate that most self pollen tubes are arrested within the first or second layer of cells of the nucellus. The probability that nucellar arrest represents a primitive feature of self-incompatibility is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-2145
    Keywords: Generative cell ; Sperm cell ; Quantitative cytology ; Mitochondria ; Plastids ; Immunofluorescence ; Actin ; Tubulin ; Video-image processing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The sperm cells of Rhododendron laetum and R. macgregoriae differentiate within the pollen tube about 24 h after germination in vitro. Threedimensional reconstruction shows that the sperm cells are paired together, and both have extensions that link with the tube nucleus, forming a male germ unit. Quantitative analysis shows that the sperm cells in each pair differ significantly in surface area, but not in cell volume nor in numbers of mitochondria or plastids. When isolated from pollen tubes by osmotic shock, the sperm cells became ellipsoidal and surrounded by their own plasma membrane, while a proportion remained in pairs linked by the inner tube plasma membrane. Both generative and sperm cells are visualized in pollen tube preparations by immunofluorescence with anti-tubulin and anti-actin monoclonal antibodies (MAbs) combined with H33258 fluorescence of the nuclei. Video-image processing shows the presence of an axial microtubule cage in the generative cells, and some microtubules are present in the cytoplasmic extensions that clasp the tube nucleus. Following sperm cell division, the extensive phragmoplast between the sperm nuclei is partitioned by the plasma membranes.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Sexual plant reproduction 4 (1991), S. 155-165 
    ISSN: 1432-2145
    Keywords: Breeding system ; Fertilization ; Floral development ; Pollination ; Rhododendron ; Seed production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The reproductive development of Rhododendron macgregoriae F.v.M., Section Vireya (Ericaceae) has been followed from 10 days before anthesis to the production of mature germinable seeds about 145 days after anthesis. The species is self-compatible but shows both protandry and physical separation of pollen from the receptive stigma. Pollen is mature and viable from shortly before anthesis until the corolla and attached anthers abscise some 9–12 days after the flowers open. Spontaneous dehiscence, however, occurs mostly in the first few days after opening. The stigma becomes receptive 6–7 days after anthesis, and nectar is produced at this time. Female gametophytes are not mature until about 10 days after anthesis. Fertilization occurs about 6–7 days after pollination, and although the endosperm commences development immediately, development of the embryo proper does not begin until some 40–45 days later. Pollinations made with fresh pollen between 5 and 14 days after anthesis were successful, but those made on dry stigmas in the first 4 days after anthesis, or on senescing pistils 21 days after anthesis, gave little or no seed set. In nature, autogamy is probably uncommon, the majority of pollinations are likely to be geitonogamous, but there is considerable potential for outcrossing.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Plant ecology 23 (1971), S. 361-368 
    ISSN: 1573-5052
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Phytosociological studies of certain meadows occurring above the tree line in N.W. Himalayas have been made. A close relationship of the ground cover with moisture, the thickness of soil cover and the amount and retention period of snow has been observed. Tendencies towards stunted growth and perennialism are universal among the plants in these loialities.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Plant ecology 23 (1971), S. 361-368 
    ISSN: 1573-5052
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Phytosociological studies of certain meadows occurring above the tree line in N.W. Himalayas have been made. A close relationship of the ground cover with moisture, the thickness of soil cover and the amount and retention period of snow has been observed. Tendencies towards stunted growth and perennialism are universal among the plants in these loialities.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Plant ecology 28 (1973), S. 19-39 
    ISSN: 1573-5052
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The present investigation is an attempt at understanding the community structure and dry matter production of seven meadowlands in and around Srinagar. A great number of species have been recorded at sites subject to some kind of biotic interference like clipping, mowing, scraping, etc., though in moderate measures only. The maximum biomass (165 g/sq.m) is also obtained at sites with high biotic interference as compared to that at protected sites (37–42 g/m2). Periodic clipping which enhances the vegetative spread of many grass species and forbs, helps in increasing the overall production at various sites. A direct correlation is observed between the importance value index and biomass of plants as the dominants contribute maximum towards the overall production at each site. The effects of varying shade on IVI of the constituent species as well as on the total production at different sites are discussed. The dry matter production under medium shade with high biotic interference is comparatively higher than that at exposed sites.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Tropical animal health and production 26 (1994), S. 187-192 
    ISSN: 1573-7438
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé La progestérone a été recherchée dans des échantillons de lait prélevés avant et 6, 20, 22 et 24 jours après insémination de vaches (zébu) Tharparkar et Sahiwal, de métis Suisse Karan (Sahiwal × Brown Suisse), Karan Fries (Tharparkar × Holstein Frison) et de bufflesses Murrah, en utilisant ELISA pour déterminer la fiabilité du diagnostic de gestation ou non dans chacun des 3 groupes d'animaux. La fiabilité du diagnostic de gestation a été nettement améliorée chez les vaches lorsque les valeurs de progestérone du lait aux 20e 22e et 24e jours ont été regroupées, et encore améliorée lorsque les valeurs avant insémination et aux 6e, 203, 22e et 24e jours ont été examinées ensemble, particulièrement chez les métis. En revanche les échantillons provenant des bufflesses ont montré le degré le plus élevé de fiabilité lorsqu'ils ont été prélevés le 24e jour et l'amélioration a été minimale quand les valeurs ont été considérées sur les 5 jours, c'est-à-dire avant et aux 6e, 20e, 22e et 24e jours après insémination. En général, la fiabilité du diagnostic positif de gestation était plus importante chez les vaches zébus (90,9 p.100), suivies par les métis (86,6 p.100) et les bufflesses Murrah (76,5 p.100) lorsque les valeurs de progestérone du lait étaient examinées sur les 5 jours. La fiabilité pour le diagnostic de non gestation était de 100 p.100 sur tous les jours. Les résultats font penser que la longueur du cycle oestral varie plus chez les bovins que chez les bufflesses et que la mortalité des embryons est plus élevée chez les buffles que chez les bovins.
    Abstract: Resumen Por medio de la prueba ELISA, se examinaron muestras para detectar progesterona en leche colectada los dias 0, 6, 20, 22 y 24 después de la inseminación, de 4 grupos de animales: cebú Sahiwal, cebú Tharparkar, Karan Suizo (Sahiwal × Pardo Suizo), Karan Fries (Tharparkar × Holstein Friesian) y vacas búfalo de la raza Murrah. La precisión en el diagnóstico de preñez se mejoró marcadamente cuando los valores de progesterona en la leche tomados en los días 20, 22 y 24 se consideraron juntos, mejorándose aún más cuando los niveles de progesterona tomados los días 0, 6, 20, 22 y 24 se consideraron juntos, particularmente en vacas cruzadas. En contraste, las vacas búfalo presentaron la precisión más alta cuando las muestras tomadas el día 24 fueron examinadas, siendo la precisión encontrada mínima cuando los valores fueron considerados a los cinco días pos-inseminación. La precisión en el diagnóstico fue más alta en vacas cebú (90·9%), seguida de las vacas cruzadas (86·6%) y por los búfalos (76·5%), cuando se consideraron los valores tomardo los 5 días. La precisión para el diagnóstico de preñez negativa fue 100% todos los días. Los resultados sugieren que existe una differencia significativa entre la duración del estro en ganado vs búfalos, presentándose una mayor mortalidad embrionaria en búfalos que en ganado bovino.
    Notes: Summary Milk samples collected on days 0, 6, 20, 22 and 24 post insemination from Sahiwal and Tharparkar (zebu) cows, Karan Swiss (Sahiwal × Brown Swiss) and Karan Fries (Tharparkar × Holstein Friesian) crossbred cows and Murrah buffaloes were analysed for progesterone by enzyme-linked immunosorbent assay to determine the accuracy of pregnancy and non pregnancy diagnosis in each of the 3 groups of animals. The accuracy of pregnancy diagnosis was markedly improved in cows when the milk progesterone values on days 20, 22 and 24 were considered together, and a further improvement when the levels on days 0, 6, 20, 22 and 24 were considered together particularly in crossbred cows. In contrast, buffaloes exhibited the highest degree of accuracy from samples collected on day 24, and improvement in accuracy was minimal when values were considered for all 5 days, viz. 0, 6, 20, 22 and 24 post insemination. Overall, the accuracy of positive pregnancy diagnosis was greatest in zebu cows (90·9%) followed by crossbred cows (86·6%) and Murrah buffaloes (76·5%) when milk progesterone values on all 5 days were considered. The accuracy for negative pregnancy diagnosis was 100% on all days. The results suggest that there is a greater variability in oestrous cycle length in cattle than in buffaloes, and embryonic mortality is greater in buffaloes than in cattle.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...