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  • 1990-1994  (15)
  • 1960-1964  (5)
  • Life and Medical Sciences  (18)
  • Ideal free distribution  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Uganda kob mating success does not increase on larger leks (1994)
    Springer
    Behavioral ecology and sociobiology 34 (1994), S. 451-459 
    Details
    ISSN: 1432-0762
    Keywords: Lek-breeding ; Mating systems ; Socioecology ; Ideal free distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract One explanation for the movement of sexually receptive females to clusters of male territories in lek-breeding species is that larger clusters provide females with higher-quality mating partners, as would be the case if males were distributed between leks in an ideal free distribution for unequal competitors. This ideal free model of lek evolution predicts that male competitive ability and mating success will be greater on larger leks than smaller ones. I tested these predictions by comparing the mean number of males on 19 different Uganda kob leks with the sex ratio, the availability of oestrous females, mating rates, male fighting rates and male turnover rates. Contrary to the predictions of the model, numbers of females, receptive females and fights increased proportionally with lek size, but were no greater per male on larger leks. Multivariate analyses of male and female numbers on leks showed that male numbers were associated with female numbers, female numbers in the past, and a variety of habitat variables which may have related to the costs of holding a lek territory, but female numbers varied only with male numbers and female density in the area. These data do not provide evidence that females gain access to superior males by mating on larger leks, though they do support the possibility that lekking may be promoted by a tendency for larger leks to retain females longer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00167337
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Uganda kob mating success does not increase on larger leks (1994)
    Springer
    Behavioral ecology and sociobiology 34 (1994), S. 451-459 
    Details
    ISSN: 1432-0762
    Keywords: Key words: Lek-breeding ; Mating systems ; Socioecology ; Ideal free distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract. One explanation for the movement of sexually receptive females to clusters of male territories in lek-breeding species is that larger clusters provide females with higher-quality mating partners, as would be the case if males were distributed between leks in an ideal free distribution for unequal competitors. This ideal free model of lek evolution predicts that male competitive ability and mating success will be greater on larger leks than smaller ones. I tested these predictions by comparing the mean number of males on 19 different Uganda kob leks with the sex ratio, the availability of oestrous females, mating rates, male fighting rates and male turnover rates. Contrary to the predictions of the model, numbers of females, receptive females and fights increased proportionally with lek size, but were no greater per male on larger leks. Multivariate analyses of male and female numbers on leks showed that male numbers were associated with female numbers, female numbers in the past, and a variety of habitat variables which may have related to the costs of holding a lek territory, but female numbers varied only with male numbers and female density in the area. These data do not provide evidence that females gain access to superior males by mating on larger leks, though they do support the possibility that lekking may be promoted by a tendency for larger leks to retain females longer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00167337
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Middle-ear development: II. Morphometric changes in the conducting apparatus of the chick (1992)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 212 (1992), S. 257-267 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ontogeny of various middle-ear structures was examined in 11 groups of chicks between 10 days embryonic and adult. Measurements of the tympanic membrane surface area and height, columella length, and that of the columella footplate, annular ligament, and oval window area were obtained using video micrographs and computer digitization techniques. The oval window matures first at 53 days post-hatching, whereas the columella achieves adult size at 74 days. The tympanic membrane surface area is the last middle-ear variable studied to reach adult size (79 days post-hatch). The columella increases its length from 0.63 mm (10 days embryonic) to 2.73 mm in the adult. The tympanic membrane area expands by 280% whereas the columellar footplate area increases by 11x. As a result, the pressure amplification of the middle ear due to the tympanic membrane/columellar footplate area ratio improves by over 400%. These data further contribute to our understanding of the functional development of the middle ear. © 1992 Wiley-Liss, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052120305
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  • 4
    Electronic Resource
    Electronic Resource
    A comparison of the metalophilic reticuloendothelial cells to cells containing acid phosphatase and non-specific esterase in the lymphoid nodules of normal and stimulated rat spleensMaterials were purchased on grant no. 407 from the American Medical Association. (1964)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 149 (1964), S. 269-277 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: This study was undertaken to determine the relationship between Marshall's metalophilic reticular cells and the cells exhibiting non-specific esterase and acid phosphatase activity in the rat spleen. Untreated and stimulated animals were used. Observations were made chiefly on the marginal metalophils of Snook. These cells showed strong acid phosphatase activity but only slight non-specific esterase activity in untreated animals. Following stimulation non-specific esterase activity increased in these cells. Within the nodules metalophilic reticular cells were always more numerous than cells with enzyme activity. Many of these metalophilic cells developed enzyme activity following stimulation. By the use of a restaining technique it was shown that all reticular cells possessing enzyme activity were also metalophilic but that the converse was not true. No mitotic activity was present in these cells.The results suggest that Marshall's metalophils are cells of the reticuloendothelial system in various stages of maturation and that, following stimulation, they may differentiate into mature phagocytic cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091490209
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    Paper (German National Licenses)
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  • 5
    Electronic Resource
    Electronic Resource
    Vaginal cycles in the rat after x-ray or other damage to one or both ovariesAided by grants from National Institutes of Health, United States Public Health Service and the University of Illinois Research Board, The Graduate College. (1962)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 144 (1962), S. 287-293 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Damage to the rat ovary at 60 days of age causes irregularities in the estrous cycle and leads to continuous cornification of the vagina. These vaginal changes occurred within two to three months after bilateral irradiation (800 or 2,000 r) or after bilateral castration and autotransplantation of a portion of one ovary. Unilateral irradiation or ligation of the ovarian arteries at their junction with the uterine artery produces similar changes within five to seven months. Comparable vaginal changes did not occur in control animals until they reached the age of ten months.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091440403
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  • 6
    Electronic Resource
    Electronic Resource
    Number of rat ova implanting after sub-sterilizing X-irradiation of one or both ovariesAided by grants from National Institutes of Health, United States Public Health Service and the University of Illinois Research Board, The Graduate College. (1963)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 146 (1963), S. 257-261 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Irradiation with 800 r of x-ray was applied to the exteriorized left ovary, to both ovaries or to the left ovary after unilateral (right) castration of 60day old rats. Treated females were placed with the male at 60, 70, 80 or 90 days of age. Females were explored at eight or nine days after sperm were found in the morning smears to determine the number of implanations.The number of matings was reduced during the period of normal vaginal cycles. Matings did occur after the unset of continuous vaginal cornification.Animals with an irradiated left and a normal right ovary maintained an average number of implantations through pregnancies one to seven. The normal ovary compensated for the loss of production by the irradiated ovary. Bilateral irradiation caused a decrease in implantations in the second and third pregnancies. In individual cases, however, thenormal complement for a single ovary occurred as late as 201 days after irradiation. The irradiated ovary in the absence of the other ovary compensated by producing more implantations; its period of production was limited to 31 days following irradiation.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091460312
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  • 7
    Electronic Resource
    Electronic Resource
    Middle-ear development VI: Structural maturation of the rat conducting apparatus (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 239 (1994), S. 475-484 
    Details
    ISSN: 0003-276X
    Keywords: Middle ear ; Auditory ; Hearing development ; Ossicles ; Tympanic membrane ; Rat (Long Evans strain) ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: The contribution of middle-ear development to the overall development of hearing has not been explored in great detail. This presentation describes the maturation of conductive elements in the rat middle ear, and provides the basis on which future studies of middle-ear functional development will follow.Methods: The middle-ear apparatus was examined at nine different ages (between 1 and 80 days postpartum) in Long Evans rats. At each age elements of the conducting apparatus were observed with either light or scanning electron microscopy (SEM), and quantitative measurements were made from video enhanced photomicrographs. Tympanic membrane area and cone depth, the length of the malleus and incus arms, ossicular weight, stapes foot plate and oval window areas, and bulla volume were all measured. Development of the area and lever ratios were derived from these measurements. The data were fitted to exponential equations and the time in days required to reach 90% of the adult level determined.Results: The pars tensa achieved 90% of total area by 17 days. The oval window achieved the 90% criterion by 13 days, while the area ratio was within 10% of its adult size by 8 days. The ossicles took between 26 and 34 days, while bulla volume took 59 days to reach the 90% level.Conclusions: Middle-ear growth was very orderly and systematic in the data reported. When maturation of the area ratio was considered against development of the endocochlear potential or the round window compound action potential, it was clear that the growth of this important aspect of the middle ear preceded the onset of cochlear function. © 1994 Wiley-Liss, Inc.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092390413
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  • 8
    Electronic Resource
    Electronic Resource
    Distribution of ova in the rat uterusThis work was supported by a grant from the University of Illinois Research Board, The Graduate College. (1962)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 143 (1962), S. 239-241 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091430308
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  • 9
    Electronic Resource
    Electronic Resource
    Immunohistochemical localization of atrial natriuretic peptide in the developing and adult mammalian kidney (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 190 (1991), S. 182-191 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The discovery, within the last decade, of atrial natriuretic peptide (ANP), a family of peptides with natriuretic/diuretic and vasorelaxant properties, has prompted much research into the mechanisms and sites of action of ANP within the kidney. In the present study, ANP was localized in the kidneys of several mammalian species by immunohistochemical techniques (1) to identify possible sites of synthesis; (2) to compare the localization of ANP to known physiological effects; (3) to determine species differences, if any, in ANP localization; and (4) to study the development of ANP immunoreactivity in the fetal and neonatal rat kidney. Using an antibody against rat ANP IV, ANP was localized exclusively on the proximal convoluted tubule (PCT) brush border and within intercalated cells of the outer medullary and cortical collecting tubules and ducts of adult mouse, rat, pig, monkey, and human kidneys. The development of ANP immunoreactivity paralleled the differentiation and maturation of collecting duct epithelium in rat fetal kidney. Atrial natriuretic peptide found within intercalated cells of the cortical and outer medullary collecting ducts may be the result of endogenous synthesis and, following secretion, may be available to receptors in the inner medullary collecting ducts.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1001900207
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  • 10
    Electronic Resource
    Electronic Resource
    Effects of temperature and body size upon heart rate and oxygen consumption in turtlesThis investigation conducted at the Dept. of Zoology, Tulane University, New Orleans, La., under grants from the National Institutes of Health and the Louisiana Heart Association. (1960)
    Philadelphia : Wiley-Blackwell
    Journal of Cellular and Comparative Physiology 55 (1960), S. 87-93 
    Details
    ISSN: 0095-9898
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1030550110
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