Mitosis in Pellia, by Charles J. Chamberlain ...

Chamberlain, Charles J.

doi:10.5962/bhl.title.21141

Cited by 6 publications

(9 citation statements)

References 7 publications

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“…(1) In some cases they have been regarded as stores of material which contribute to the building of the chromosomes in prophase (2,3), while in other cases this, explanation has been rejected. Another view, supported by Strasburger and Chamberlain (4,5) amongst others, is that spindle-formation is a function of the nucleoli. Others again hold that extruded portions of the nucleolus are converted into organs such as the blepharoplast of Hepaticce.…”

Section: Historicalmentioning

confidence: 79%

The nucleolus of tmesipteris tannensis , bernh

Yeates

1925

Proc. R. Soc. Lond. B.

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In some slides from young synangia of Tmesipteris , prepared from curiosity regarding this unique plant, it was noticed that during mitosis there were present, in addition to the chromosomes, several rounded bodies similar to the nucleoli of resting cells. Moreover, nucleoli were present in nuclei where the spireme was fully developed prior to mitosis. Preliminary examination thus suggested Tmesipteris as a most favourable plant for a study of the nucleolus as regards its relationship to the chromosomes and its behaviour during mitosis. Historical . The study of plant-nucleoli has been largely incidental to the investigation of chromosome behaviour, more especially during the meiotic divisions. The general conclusions from the study of plant-nucleoli may be summarised thus:— The number of nucleoli per cell may vary from one up to eight or ten, some of which may arise by the division of pre-existing ones. (1) In some cases they have been regarded as stores of material which contribute to the building of the chromosomes in prophase (2, 3), while in other cases this, explanation has been rejected. Another view, supported by Strasburger and Chamberlain (4, 5) amongst others, is that spindle-formation is a function of the nucleoli. Others again hold that extruded portions of the nucleolus are converted into organs such as the blepharoplast of Hepaticœ . Extrusion of chromidia into the cytoplasm by nucleoli has been described by various cytologists (6, 7), and Digby (1) finds that the nucleolus of Galtonia is closely related to one pair of chromosomes, and at metaphase is “pushed” away from the equatorial plate on the end of a chromosome. Lack of genetic continuity between nucleoli has been advocated by many authors, especially by Gates (8, 9, 10) and by Mottier (11).

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Section: Historicalmentioning

confidence: 79%

The nucleolus of tmesipteris tannensis , bernh

Yeates

1925

Proc. R. Soc. Lond. B.

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“…In order to obtain sinusoidal PM it is necessary to mount one of the interferometer mirrors (usually the fixed mirror in a standard system M2) on a lousdpeaker coil and apply a sinusoidal voltage to the coil. It can be shown (Chamberlain 1971) that for a modulation of amplitude p and frequency f given by…”

Section: Methodsmentioning

confidence: 99%

“…(3) k, is a constant dependent on the details of the synchronous detection, p (u) is the power spectrum of the energy reaching the detector, u is the radiation wave-number (cm-') and y is the optical path-difference (cm). The first maximum of the function (3) is chosen to coincide with the maximum of the beam-divider characteristic by adjustment of p o (Chamberlain 1971).…”

Section: Methodsmentioning

confidence: 99%

“…The presence of the multiplicative PM characteristic function does not interfere with the analysis of the spectra, but, in fact, improves their quality in some respects. The advantages of PM (namely the more efficient use of the available radiation, and the removal of problems associated with multiplicative noise) are considered in detail by Chamberlain (1971).…”

Section: Ka (4)mentioning

confidence: 99%

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Measurements of submillimetre wavelength radiation emitted by the stratosphere

HARRIES

BURROUGHS

1971

Quarterly Journal of the Royal Meteorological Society

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Observations have been made of the submillimetre wavelength radiation emitted by the lower stratosphere, using techniques of Fourier transform spectroscopy, while flying in a Comet 2E aircraft. Using the method of phase-modulation high quality spectra have been obtained at several altitudes over the spectral range 20 to 66 cm-I, and these have enabled identification of many emission lines due to O2 and Oj, in addition to those of H,O. Also several unidentified emission lines have been observed. The meteorological applications of this spectroscopic technique are considered. In particular, a direct method of comparing the emission of 'strong' water-vapour and oxygen lines enables a calculation of mixing ratio of water vapour in the stratosphere to be made, and a value of (2.1 f-0.3) x g/g is derived above an altitude of 12.2 km. A similar comparison for omne has given an integrated concentration of 0.35 & 0.10 cm atm in the vertical path above the observer. The merits of these observations in measuring stratospheric mixing ratios are discussed with respect to alternative techniques, in particular with reference to balloon-borne studies. ' Stratospheric humidity as determined from the absorption of solar radiation by a resolved spectral structure of water vapour I , Izu. Atm. Ocean. Phys., 4, pp. 826-834. ' Measurements of atmospheric infrared emission with a balloon-borne multifilter radiometer ', Quart. J. R. Met. ' Solid state devices for infrared detection ', J. Sci. Instruments, ' The width of the water vapour absorption line at A = 0-92 mm ', Sou. Radiophysics, 9, pp. 621-627. ' The far infrared spectrum of D,O ', Ph. D. thesis, Ohio State University. ' Theory of the fine structure of the molecular oxygen ground state ', Phys. Rev., 97, pp. 937-951. ' Line breadths in the microwave magnetic resonance spectrum of oxygen ', Ibid., 99, pp. 537-539. ' Fourier spectroscopy ', Prog. in Opt., 6, pp. 261-330. ' Radiometric measurements of emission from stratospheric water vapour I , Quart. J. R. Met. SOC., 91, pp, 330-338. ' Pure rotation spectrum of water vapour ', Report ERDA-2, Environmental Studies Dept., U. S. Army, White Sands, N. Mexico. ' Moisture contamination at altitude by balloon and associated equipment I , J. Geophys. Res., 71, pp. 3,775-3,778. SOC., 95, pp. 535-543. 43, pp. 857-868.

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“…Indeed, this approach of critical dialogue is harmonious both with our profession's ethical values and with a revolutionized philosophy of science for the discipline (Gergen, 1982;Margolis, Manicas, Harre, & Secord, 1986;Riegel, 1978). Relatedly, a social policy of empowerment (Rappaport, 1981) would foster direct citizen control over process and outcome (e.g., Chamberlain, 1978), autonomous mutual aid, and support networks.…”

Section: Preventing Vs Entrenching Iatrogenesismentioning

confidence: 99%

The dark side of our moon: The latrogenic aspects of professional psychology

Walsh

1988

J. Community Psychol.

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Traditional theory, research, and practice in professional psychology not only might contradict the discipline's ideals of protecting human rights and promoting human welfare but also might produce iatrogenic effects. The harm caused by professionals' interventions can stem from ideological sources and from the quality of the human relationship between scientist‐healer and citizen. Research practices in community settings concretely illustrate professional psychologists' iatrogenic behavior. A competency‐based approach to problems in living and the promise of an altered social role for psychologists can prevent iatrogenic effects and can substantially contribute to more autonomous coping by citizens and their communities. But fundamental strains in the socialization of professional psychologists impede the development of a democratic approach. Consequently, a shift in consciousness and behavior requires support from psychologists' institutional structures.

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Mitosis in Pellia, by Charles J. Chamberlain ...

Cited by 6 publications

References 7 publications

The nucleolus of tmesipteris tannensis , bernh

The nucleolus of tmesipteris tannensis , bernh

Measurements of submillimetre wavelength radiation emitted by the stratosphere

The dark side of our moon: The latrogenic aspects of professional psychology

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