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1.
The year 2018 marks the 150th anniversary of the first publication of Julius von Sachs' (1832–1897) Lehrbuch der Botanik (Textbook of Botany), which provided a comprehensive summary of what was then known about the plant sciences. Three years earlier, in 1865, Sachs produced the equally impressive Handbuch der Experimental‐Physiologie der Pflanzen (Handbook of Experimental Plant Physiology), which summarized the state of knowledge in all aspects of the discipline known today as plant physiology. Both of these books provided numerous insights based on Sachs' seminal experiments. By virtue of a reliance on detailed empirical observation and the rigorous application of chemical and physical principles, it is fair to say that the publication of these two monumental works marked the beginning of what can be called “modern‐day” plant science. Moreover, Sachs' Lehrbuch der Botanik prefigured the ascendance of plant molecular biology and the systems biology of photoautotrophic organisms. Regrettably, many of the insights of this great scientist have been forgotten by the generations who followed. It is only fitting, therefore, that the anniversary of the publication of the Lehrbuch der Botanik and the career of “the father of plant physiology” should be honored and reviewed, particularly because Sachs established the physiology of green organisms as an integral branch of botany and incorporated a Darwinian perspective into plant biology. Here we highlight key insights, with particular emphasis on Sachs' detailed discussion of sexual reproduction at the cellular level and his endorsement of Darwinian evolution.  相似文献   

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The Life and Times of Sara Baartman: The Hottentot Venus. 1998. 52 minutes, color. film directed by Zola Maseko. For more information, contact First Run/Icarus Films. 153 Waverly Place, New York. NY 10014.  相似文献   

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The post-embryonic development of the appendages of the Cyprididae ostracod Heterocypris salina (Brady, 1868) are described in detail and compared with those of other podocope species documented in previous studies. Generally, the appearence of limbs during onotgeny of H. salina is similar to that of other species, but small differences in limb morphologies were identified between H. salina and other Cyprididae species, including other Heterocypris species. Some features appear either earlier or later in the development of H. salina compared with other species, even species of the same genus. These features may be useful characters for phylogenetic analyses at the genus and family levels.  相似文献   

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Petrov  E. A.  Kupchinsky  A. B.  Fialkov  V. A.  Badardinov  A. A. 《Biology Bulletin》2021,48(9):1704-1714
Biology Bulletin - The published information on the roles that summer hauling grounds play in the life cycle of the Baikal seal (Pusa sibirica Gmelin 1788) is reviewed and summarized. In the Baikal...  相似文献   

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J M Witkin  J E Barrett 《Life sciences》1985,37(17):1587-1595
The selective benzodiazepine receptor antagonist, Ro 15-1788, produced behavioral effects in pigeons at doses at least 100 times lower than those previously reported to possess intrinsic pharmacological activity in mammals. In contrast to its effects in mammalian species, in pigeons, Ro 15-1788 does not exhibit partial agonist activity. Key-peck responses of pigeons were studied under a multiple fixed-interval 3-min, fixed-interval 3-min schedule in which the first response after 3-min produced food in the presence of red or white keylights. In addition, every 30th response during the red keylight produced a brief electric shock (punishment). Under control conditions, punished responding was suppressed to 30% of unpunished response levels. Ro 15-1788 (0.01 mg/kg, i.m.) increased unpunished response rates by 33% without affecting rates of punished responding. Doses of 0.1 to 1.0 mg/kg Ro 15-1788 produced dose-related decreases in both punished and unpunished responding. As is characteristic of other benzodiazepines, midazolam (0.1 and 0.3 mg/kg, i.m.) markedly increased punished responding but had little effect on rates of unpunished responding. Ro 15-1788 antagonized the increases in punished responding and also reversed the rate-decreasing effects of higher doses of midazolam. However, the effectiveness of Ro 15-1788 as a benzodiazepine antagonist was limited by its intrinsic activity: rate-decreasing doses of Ro 15-1788 were unable to completely reverse behavioral effects of midazolam. Midazolam was an effective antagonist of the behavioral effects of Ro 15-1788 (up to 0.1 mg/kg) but midazolam did not influence the rate-decreasing effects of 1.0 mg/kg Ro 15-1788 across a 100-fold dose range. In the pigeon, the behavioral effects of relatively low doses of Ro 15-1788 (0.01-0.1 mg/kg) appear to be related to benzodiazepine receptor mechanisms, whereas other systems appear to be involved in the effects of higher doses.  相似文献   

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Imidazobenzodiazepine (Ro 15-1788, 5 mg/kg) similarly to a lose dose of apomorphine (0.1 mg/kg) decreased the intensity of footshock aggression in male rats. Ro 15-1788 significantly potentiated the antiaggressive action of apomorphine. Pirenperone (0.01 mg/kg) potentiated the effect of both drugs, whereas haloperidol (0.01 mg/kg) had an opposite action. After long-term treatment with apomorphine and Ro 15-1788 the tolerance to their antiaggressive action developed. This change was in agreement with increased serotonin metabolism in the forebrain. Unlike the action on aggressive behavior, Ro 15-1788 similarly to haloperidol (0.05 mg/kg) decreased the motor depressant effect of apomorphine (0.01 mg/kg) in mice. This effect correlated with the lowered serotonin metabolism after Ro 15-1788 administration. Unlike apomorphine, Ro 15-1788 reversed catalepsy induced by haloperidol (0.25 mg/kg). Administration of pirenperone (0.03 mg/kg) and destruction of serotoninergic terminals by p-chloroamphetamine (2 X 15 mg/kg) significantly potentiated the sedative action of apomorphine. It appears that different action of Ro 15-1788 on behavioral effects of apomorphine is related to different influence of Ro-1788 on serotoninergic processes in the striatum and limbic structures.  相似文献   

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The life of Joseph Dalton Hooker (1817–1911) provides an invaluable lens through which to view mid-Victorian science. A biographical approach makes it clear that some well-established narratives about this period need revising. For example, Hooker’s career cannot be considered an example of the professionalisation of the sciences, given the doubtful respectability of being paid to do science and his reliance on unpaid collectors with pretensions to equal scientific and/or social status. Nor was Hooker’s response to Darwin’s theories either straightforward or contradictory; it only makes sense as carefully crafted equivocation when seen in the context of his life and career. However, the importance of Hooker’s life is ultimately its typicality; what was true of Hooker was true of many other Victorian men of science.  相似文献   

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Inigo of Rancho Posolmi: The Life and Times of. Mission Indian. Laurence H. Shoup and Randall T. Milliken. Novato: Ballena Press, 1999.182 pp.  相似文献   

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Lilian Vaughan Morgan was an important geneticist of the firstpart of the 20th century. She discovered both the attached-Xand closed-X chromosomes as part of her extensive research onthe X chromosome of Drosophila. She received A.B and M.S. degreesin Biology from Bryn Mawr College and became an independentinvestigator in the 1890s at the Marine Biological Laboratory,Woods Hole, Massachusetts. Although her research at the turnof the century was in embryology, she made the successful transitionto genetics. In 1904 she married T. H. Morgan, raised four children,managed the Morgan household, and when the children were grownresumed full time research. She always worked independently,and in her lifetime published 16 single author papers.  相似文献   

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Petrov  E. A.  Kupchinsky  A. B.  Fialkov  V. A.  Badardinov  A. A. 《Biology Bulletin》2021,48(9):1715-1728
Biology Bulletin - Based on the literature record, some forms of the behavior of the Baikal seal (Pusa sibirica) are described, both on coastal hauling grounds and in their immediate vicinity. This...  相似文献   

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Spermiogenesis and sperm ultrastructure of adult Cyathocephalus truncatus, a member of presumably basal group of "true" cestodes (Eucestoda), have been examined for the first time by using transmission electron microscopy. The process of sperm formation corresponds in basic pattern to that of the Pseudophyllidea. In addition, the 2 pairs of electron-dense attachment zones are present in median cytoplasmic process of C. truncatus. However, mature spermatozoa of C. truncatus differ significantly from those of the pseudophyllideans, especially in the morphology of the proximal and distal spermatozoon extremities. The proximal extremity of the mature spermatozoon lacks a crested body, which is present in more derived cestodes and some pseudophyllideans. The distal end of the mature spermatozoa exhibits different morphology in the gametes from testes and those from receptaculum seminis. New for the Eucestoda is a finding that a lateral cytoplasmic extension creates the distal end of the spermatozoa from testes, resembling sperm of some Monogenea and Digenea. In contrast, the distal extremity of the spermatozoa from receptaculum seminis contains only a nucleus. Despite the above-mentioned peculiarities, the ultrastructural data on sperm/spermiogenesis suggest close relationships of the Spathebothriidea and Pseudophyllidea.  相似文献   

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The thylacine (Thylacinus cynocephalus) was Australia’s largest marsupial carnivore until its extinction within the last century. There remains considerable interest and debate regarding the biology of this species. Studies of thylacine biology are now limited to preserved specimens, and parts thereof, as well as written historical accounts of its biology. This study describes the development of the immune tissues of a pouch young thylacine, one of only eleven in existence, and the only specimen to be histologically sectioned. The appearance of the immune tissue of the developing pouch young thylacine is compared to the immune tissues of extant marsupials, providing insights into the immunity, biology and ecology of the extinct thylacine.  相似文献   

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