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Showing papers in "Nature in 1956"


Journal ArticleDOI
07 Jan 1956-Nature
TL;DR: Hanbury-Brown and Twiss as mentioned in this paper showed that photon detections in the two daughter beams were correlated: the photons were bunching together, which corresponded to a correlation in the intensity of light in two beams, which could be used to infer the angular size of distant stars.
Abstract: Classical interferometry works by detecting correlations in the phases of two waves. In Nature in 1956, R. Hanbury-Brown and R. Q. Twiss demonstrated another technique that probes quantum-mechanical correlations in the electromagnetic field. Splitting an incoherent light beam, they found that photon detections in the two daughter beams were correlated: the photons were bunching together. This corresponds to a correlation in the intensity of light in the two beams, which Hanbury-Brown and Twiss suggested could be used to infer the angular size of distant stars. Physicists now rely on the effect to probe the quantum character of complex light sources. [Obituary of Robert Hanbury Brown: Nature 416, 34 (2002)]

1,829 citations


Journal ArticleDOI
29 Sep 1956-Nature
TL;DR: Strains not producing pyocyanin, from whatever source, cannot be dismissed from consideration as Ps.
Abstract: ALTHOUGH the identification of Pseudomonas pyocyanea is generally very simple, the diagnosis of ‘atypical’ strains may take several days, and, as Schaub and Foley1 stress, “its identification may present a problem”. Yow and Townsend2, in their study on the sensitivity of Ps. pyocyanea to various antibiotics, limit the scope of their examinations: “Because of the difficulty in positively identifying the non-pigment-producing strains of Pseudomonas, only those producing either pyocyanin, fluorescin, or both, were included in this study”. However, apyocyanogenic strains are common. These strains are either primarily deficient in producing pigment or may have lost their ability to do so. Haynes3 therefore points out: “Strains not producing pyocyanin, from whatever source, cannot be dismissed from consideration as Ps. pyocyanea.”

1,444 citations



Journal ArticleDOI
24 Nov 1956-Nature

994 citations


Journal ArticleDOI
01 Apr 1956-Nature
TL;DR: The Foundations of Statistics By Prof. Leonard J. Savage as mentioned in this paper, p. 48s. (Wiley Publications in Statistics.) Pp. xv + 294. (New York; John Wiley and Sons, Inc., London: Chapman and Hall, Ltd., 1954).
Abstract: The Foundations of Statistics By Prof. Leonard J. Savage. (Wiley Publications in Statistics.) Pp. xv + 294. (New York; John Wiley and Sons, Inc.; London: Chapman and Hall, Ltd., 1954.) 48s. net.

844 citations


Journal ArticleDOI
13 Oct 1956-Nature
TL;DR: A specific chemical difference between the Globins of Normal Human and Sickle-Cell Anaemia Haemoglobin is identified and this difference is related to the ferric content of the haemoglobin molecule.
Abstract: A Specific Chemical Difference Between the Globins of Normal Human and Sickle-Cell Anaemia Haemoglobin

753 citations


Journal ArticleDOI
14 Apr 1956-Nature
TL;DR: In their experiments with bacteriophages, Hershey and Chase have shown that only the nucleic acid component plays a part in the intracellular multiplication, and indications that in simple viruses containing ribonucleic acid the nuclei acid plays a dominant part inThe infection.
Abstract: IN their experiments with bacteriophages, Hershey and Chase1 have shown that only the nucleic acid component plays a part in the intracellular multiplication. There are also indications that in simple viruses containing ribonucleic acid the nucleic acid plays a dominant part in the infection. Thus, experiments with tobacco mosaic virus have shown that the protein can be changed chemically without affecting the activity and the genetic properties2; recently, it was even found3 that part of the protein can be removed from tobacco mosaic virus without destroying the activity.

738 citations


Journal ArticleDOI
10 Mar 1956-Nature
TL;DR: Watson and Crick proposed that plant viruses consistently took one of two shapes because the two chemical components of which they were made up, ribonucleic acid surrounded by a large number of identical protein subunits, were assembled according to a general plan that was determined by "symmetry elements".
Abstract: Renewing their collaboration during Watson's return to the Cavendish laboratory in the fall of 1955, Watson and Crick in this article laid out a theory for explaining why all plant viruses whose structure had been studied up to that time were very similar in shape, either rod-shaped (cylindrical) or spherical. In developing their theory they once again benefited from their complementary expertise, namely Crick's extensive knowledge of X-ray crystallography and Watson's previous studies with tobacco mosaic virus and ribonucleic acid. They proposed that plant viruses consistently took one of two shapes because the two chemical components of which they were made up, ribonucleic acid surrounded by a large number of identical protein subunits, were assembled according to a general plan that was determined by "symmetry elements," structural requirements imposed by the shape of each protein subunit and by the angles of the bonds they formed with the ribonucleic acid core.

673 citations




Journal ArticleDOI
01 Sep 1956-Nature
TL;DR: Benard as mentioned in this paper observed a cellular deformation produced on the free surface of a liquid film the bottom surface of which (in contact with a floor) was uniformly heated and hotter than its top surface.
Abstract: IN 1900, Benard1 described his observations of a cellular deformation produced on the free surface of a liquid film the bottom surface of which (in contact with a floor) was uniformly heated and hotter than its top surface. He also observed a cellular flow associated with the deformation. These studies were made on films of thicknesses in the range 0.5–1.0 mm.

Journal ArticleDOI
10 Nov 1956-Nature

Journal ArticleDOI
01 Jul 1956-Nature
TL;DR: The corpora allata have been known as the source of a ‘juvenile hormone’ which opposes or prevents the metamorphosis of immature insects and the presence of this hormone exerts a biochemical restraint on the cellular transformations responsible for the met transformation of the insect as a whole.
Abstract: SINCE the pioneering researches of Wigglesworth1 the corpora allata have been known as the source of a ‘juvenile hormone’ which opposes or prevents the metamorphosis of immature insects. The presence of this hormone exerts a biochemical restraint on the cellular transformations responsible for the metamorphosis of the insect as a whole. These facts have been ascertained by biological procedures such as parabiosis and the transplantation of living corpora allata2. The hormone itself has apparently not been extracted or obtained apart from the living insect or endocrine organ.


Journal ArticleDOI
02 Jun 1956-Nature
TL;DR: It has been shown that the subcutaneous application of small amounts of cadmium salts results in a rapid destruction of all tissues of the testicle.
Abstract: THE physiological action of cadmium salts has been studied extensively by many authors. Morphological disturbances have been described in various organs (liver, kidney, etc.). While studying the effect of cadmium salts on protein metabolism one of us (J. P.) observed that cadmium chloride administered subcutaneously to rats produces macroscopic lesions of the testes. This seems to have escaped the notice of previous authors and therefore this phenomenon was studied more closely.

Journal ArticleDOI
13 Oct 1956-Nature
TL;DR: The introduction of n-butyl and methyl meth-acrylates as embedding media1 constituted an important development in the preparation of ultra-thin sections of biological material; but their use is attended by various major difficulties.
Abstract: THE introduction of n-butyl and methyl meth-acrylates as embedding media1 constituted an important development in the preparation of ultra-thin sections of biological material; but their use is attended by various major difficulties. Shrinkage occurs on polymerization, hard objects are not penetrated by the monomer so that the plastic shrinks away and does not provide sufficient support, and sometimes there is an unaccountable appearance of bubbles around the specimen. Moreover, the polymerization process is not uniform and sometimes causes severe damage. This is perhaps most strikingly seen in bacteria where often only empty remnants of cell walls remain.

Journal ArticleDOI
24 Mar 1956-Nature
TL;DR: This work has shown that the growth of Aerobacter aerogenes in the presence of proflavine or crystal violet gives rise to new populations of cells, which, although biologically indistinguishable from the original strain, have a distinctive electrometric behaviour.
Abstract: DIFFERENCES between the behaviour of normal fibroblasts and sarcoma cells have been observed in tissue culture by Abercrombie and Heaysman1. Normal fibroblasts affect each other's movements by contact inhibition, whereas sarcoma cells do not show inhibition either with respect to each other or to normal fibroblasts. Time-lapse colour films taken with the interference microscope (shown at the Bristol meeting (1955) of the British Association by E. J. Ambrose and M. Abercrombie) have shown that this difference in behaviour is due to differences in the mechanism of contact formation in the two cases, being dependent upon a loss of adhesiveness of the cell surface of the tumour cells. This reduction in the adhesiveness of the tumour cell suggests that the electrical properties of the surface may have altered during the malignant transformation. These properties may be investigated by electrophoretic measurements of cellular mobility. For example, studies of bacteria during growth, in the presence of bacteriostatic agents, have revealed marked changes in the nature of the cell surface, changes which are passed on to the progeny during subsequent growth, either in the presence or the absence of the drug. Thus the growth of Aerobacter aerogenes in the presence of proflavine2 or crystal violet3 gives rise to new populations of cells, which, although biologically indistinguishable from the original strain, have a distinctive electrometric behaviour.

Journal ArticleDOI
03 Mar 1956-Nature
TL;DR: The investigation of the high affinity of chlorotetracycline and oxytetracyCline for the cations of heavy metals has been extended to the parent substance, tetracy Cline, with the results shown in Table 1, which also includes some new values for the substituted tetrACYclines.
Abstract: THE high affinity of chlorotetracycline (aureomycin) and oxytetracycline (terramycin) for the cations of heavy metals has been reported1. This investigation is now extended to the parent substance, tetracycline, with the results shown in Table 1, which also includes some new values for the substituted tetracyclines.


Journal ArticleDOI
01 May 1956-Nature
TL;DR: In this article, the capacitance of a cylindrical system was investigated and it was shown that capacitance depends on one length only to the first order, provided the asymmetry was not too great, a standard capacitor could be constructed which required only one length measurement for the computation of its capacitance.
Abstract: ALTHOUGH capacitance has the dimensions of length only, usually two or more separate lengths are needed to compute the capacitance of the various forms that have been used as standards. In seeking aform of calculable capacitor involving a minimum number of determinations of length, we have investigated cylindrical systems and have discovered a particular class of capacitor in which the capacitance depends on one length only to the first order. For example, if a square cylinder is constructed from four conducting planes which are insulated from each other at the corners, then the direct capacitances per unit length of cylinder, between each pair of opposing inside faces, are equal and independent of the size of the square. This direct capacitance was calculated as cm./cm., and it was also calculated that if the cross-section was rectangular with a ratio of sides of 1 + δ, δ ≪ 1, then the mean of the two cross-capacitances was cm./cm. These calculations confirmed that, providing the asymmetry was not too great, a standard capacitor could be constructed which required only one length measurement for the computation of its capacitance. The length of the capacitor may be defined by insulating a length of one face from the remainder of that face, which remainder functions as a guard.


Journal ArticleDOI
29 Sep 1956-Nature
TL;DR: Basic formulations applying mass-action considerations to the differentiation of types of inhibition are those of Gaddum, applied largely to tissue and organ responses, and of Linweaver and Burke, which have been applied both to relatively simple enzyme systems and to complex responses of tissues and of intact animals.
Abstract: ONE of the cornerstones of all quantitative applications of classical receptor theory has been the postulate that the response of a given organ or tissue is proportional to the number of receptors occupied by the activating agent, and that the maximal response occurs when all receptors are occupied. Although never proved experimentally, and perhaps a priori somewhat unlikely in view of the complex nature of tissue responses, this relationship is necessary if agonist dose – response curves are to be explained in terms of mass-action equilibria, and it provides the basis for differentiating reversible competitive from non-competitive or irreversible inhibition. Basic formulations applying mass-action considerations to the differentiation of types of inhibition are those of Gaddum1, applied largely to tissue and organ responses, and of Linweaver and Burke2, which have been applied both to relatively simple enzyme systems and to complex responses of tissues and of intact animals.


Journal ArticleDOI
29 Sep 1956-Nature
TL;DR: The identity of haptoglobin and the proteins characterizing the serum groups can be regarded as established, even though previous work had not shown the multiple nature of haPToglobin.
Abstract: SEVERAL workers1–3 have described the presence in serum of a protein with the striking characteristic of binding haemoglobin. During electrophoresis on filter paper, this haemoglobin-binding protein migrates in the α2-globulin position. It is the haptoglobin of Jayle et al. 1. The serum-protein groups described by Smithies4,5 are characterized by several proteins demonstrated by electrophoresis in starch gels which also have this property of binding haemoglobin. They appear to be the only serum proteins with haemoglobulin-binding powers. Furthermore, they also migrate in the α2-globulin position when the electrophoresis is carried out on filter paper5,6. Consequently, the identity of haptoglobin and the proteins characterizing the serum groups can be regarded as established, even though previous work had not shown the multiple nature of haptoglobin. The serum-protein groups are therefore basically determ ined by differences in the haptoglobins of different individuals.

Journal ArticleDOI
14 Jan 1956-Nature
TL;DR: TUBAL mouse ova at the eight-cell stage developed consistently to blastulse, when cultured in the egg white–saline mixture used by Hammond, but no growth was obtained in the Krebs–Ringer bicarbonate alone.
Abstract: TUBAL mouse ova at the eight-cell stage developed consistently to blastulse, when cultured in the egg white–saline mixture used by Hammond1 for the actual collection of ova. This fluid was freshly prepared each day and kept in tightly stoppered vessels. Unlike that of Hammond, the pH was about 7.0; but this rapidly rose to 7.8 during measurement with a glass electrode or when exposed in shallow vessels, and the change was attributed to loss of carbon dioxide contained in the egg white. Since ova failed to differentiate at a pH greater than 7.7, Krebs–Ringer bicarbonate2 (pH 7.4), with 10 γ/ml. penicillin and streptomycin, was adopted as the standard saline medium. With the addition of 1 per cent fresh thin egg white, this proved an excellent culture medium for the ova, but no growth was obtained in the Krebs–Ringer bicarbonate alone.

Journal ArticleDOI
22 Dec 1956-Nature
TL;DR: To study further the specificity of gold thioglucose in causing ventromedial hypothalamic lesions and hyperphagia the action of other gold thio compounds was examined, in particular a compound where thegold thio moiety is linked to a radical very similar to glucose.
Abstract: IN a recent publication1 it was shown that gold thioglucose produces lesions in the ventromedial hypothalamic area of injected mice. It had previously been shown2 that gold thiomalate, although similar to gold thioglucose with respect to toxicity, gold content and molecular weight, does not cause obesity; its injection does not lead to hypothalamic lesions1. To study further the specificity of gold thioglucose in causing ventromedial hypothalamic lesions and hyperphagia the action of other gold thio compounds was examined, in particular a compound where the gold thio moiety is linked to a radical very similar to glucose, namely, gold thiosorbitol (supplied through the kindness of Abbott and Co.), and compounds where the gold thio moiety is linked to metabolites other than glucose: besides gold thiomalate, gold thiocaproic acid and gold thioglycerol were available (also supplied by Abbott and Co.). The effects of gold thioglycoanilide and gold sodium thiosulphate were also examined. The main dose of each compound used in these experiments was calculated to provide as much gold as is contained in the dose of gold thioglucose found most effective to yield obese mice. (In a series of 800 Swiss mice treated with gold thioglucose 1 mgm./gm. body-weight was found to induce obesity in 60 per cent of surviving mice and varying degrees of ventromedial hypothalamic damage in all animals examined.) For each compound in addition to the main dose a number of multiples and fractions of this standard dose were used.


Journal ArticleDOI
07 Jan 1956-Nature
TL;DR: Since the adrenergic nerves may be regarded as homologues of the adrenal medullary cells, it may be expected that their specific action substance is similarly stored in the terminal parts of the nerves.
Abstract: THE presence of sympathomimetic activity in adrenergic nerve tissue has been demonstrated by several authors1. The active substance later was shown to possess the characteristic biological and chemical properties of noradrenaline2. A comparison of the relative contents of noradrenaline in splenic nerves (10–20 µgm. per gm.) and the spleen (2–4 µgm. per gm.) suggests that the transmitter is accumulated in the terminal parts of the nerves. Certain substances, such as acids, detergents and digitonin, which release catechol amines from adrenal medullary cell granules3, also release the adrenergic transmitter from a perfused organ4. Moreover, since the adrenergic nerves may be regarded as homologues of the adrenal medullary cells, it may be expected that their specific action substance is similarly stored.

Journal ArticleDOI
Karl Popper1
01 Mar 1956-Nature
TL;DR: In this paper, it was shown that all irreversible mechanical processes involve an increase of entropy, and that classical mechanics can describe physical processes only in so far as they are reversible in time.
Abstract: IT is widely believed that all irreversible mechanical processes involve an increase of entropy, and that ‘classical’ (that is, non-statistical) mechanics, of continuous media as well as of particles, can describe physical processes only in so far as they are reversible in time1. This means that a film taken of a classical process should be reversible, in the sense that, if put into a projector with the last picture first, it should again yield a possible classical process.