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1.
Summary According to recent geological and paleontological investigations thePithecanthropus-beds of Java are pleistocene in age. The examinations of the fossil mammalian faunæ of the island are of utmost importance for this age-determination and the following faunæ can be recognized:Tji Djolang-fauna: Middle Pliocene.Kali Glagah-fauna: Upper Pliocene.Djetis-fauna withPithecanthropus: Lower Pleistocene.Trinil-fauna withPithecanthropus: Middle Pleistocene.Ngandong-fauna withHomo neanderthalensis soloensis: Upper Pleistocene.Sampoeng-fauna with a primitive type of the Wedda-Dravida-Australoid group: Subrecent. — Micropaleontological examinations of smallerForaminifera from marine equivalents of thePithecanthropus-beds confirm the age-determinations based on mammalia. — Recent field investigations prove that the lower and middle pleistocenePithecanthropus-beds are distinctlyfolded by a post-middle-pleistocene movement; the upper pleistocene Ngandong-terraces are not folded at all.  相似文献   

2.
Summary Scabies and demodicosis of dogs as well as phthiriasis of pigs, dogs, and cattle may be cured by peroral application of contact poisons (di-trichlorphenyl-dichlorpropanon and bis-parachlorphenyl-trichlorbutan). Dose 0,1–0,2 g/kg body-weight during 2–4 days. In case of demodicosis the cure must be repeated 1–2 times in short intervalls. On peroral application the drugs may be detected within a few hours in the milk, fæces, and urine. The milk of the cow contains the drug during 7 to 8 days after peroral medication.  相似文献   

3.
Summary C. auronitens has 26 autosomes (2n), from which one pair — calledA-chromosomes — is relatively long.A-chromosomes consist of an euchromatic and a heterochromatic arm. In 63% of the individuals, theA-chromosomes are intraindividually anisomorph with regard to the length of their heterochromatic arm. According to its length, this arm shows 0–3 secondary constrictions. Hence there are at least 4 different forms of theA-chromosome.  相似文献   

4.
After decades of neglect philosophers of physics have discovered gauge theories—arguably the paradigm of modern field physics—as a genuine topic for foundational and philosophical research. Incidentally, in the last couple of years interest from the philosophy of physics in structural realism—in the eyes of its proponents the best suited realist position towards modern physics—has also raised. This paper tries to connect both topics and aims to show that structural realism gains further credence from an ontological analysis of gauge theories—in particular U(1) gauge theory. In the first part of the paper the framework of fiber bundle gauge theories is briefly presented and the interpretation of local gauge symmetry will be examined. In the second part, an ontological underdetermination of gauge theories is carved out by considering the various kinds of non-locality involved in such typical effects as the Aharonov–Bohm effect. The analysis shows that the peculiar form of non-separability figuring in gauge theories is a variant of spatiotemporal holism and can be distinguished from quantum theoretic holism. In the last part of the paper the arguments for a gauge theoretic support of structural realism are laid out and discussed.  相似文献   

5.
Summary Using the properties of the Centre of Gravity to obtain geometrical results goes back to Archimedes, but the idea of associating weights to points in calculating ratios was introduced by Giovanni Ceva in De lineis rectis se invicem secantibus: statica constructio (Milan, 1678). Four years prior to the publication of Ceva's work, however, another publication, entitled Geometria Magna in Minimis (Toledo, 1674), 2 appeared stating a method similar to Ceva's, but using isomorphic procedures of a geometric nature. The author was a Spanish Jesuit by the name of Joseph Zaragoza.Endeavouring to demonstrate an Apollonius' geometrical locus, Zaragoza conceived his idea of centrum minimum — a point strictly defined in traditional geometrical terms — the properties of which are characteristic of the Centre of Gravity. From this new concept, Zaragoza developed a theory that can be considered an early draft of the barycentric theory that F. Mobius was to establish 150 years later in Der barycentrische Calcul (Leipzig, 1827).Now then, whereas Ceva's work was rediscovered and due credit was given him, to this day Zaragoza's work has remained virtually unnoticed.  相似文献   

6.
Summary A transplant consisting of the rudiment of a cloaca with some somatic material implanted at a certain distance ventral from the normal route taken by the pronephric duct can be the cause of a deviation of the duct from its normal course. The pronephric duct grows towards the secondary protodæum, whereas the duct is lacking in the part of the body behind the secondary proctodæum. It seems that the proctodæum exercises an attractive effect on the growing pronephric duct.The results of the experiments, at any rate, are in favour of the conception ofO'Connor (1938) andVan Geertruyden (1942), who found that the pronephric duct develops by its own independent growth. I cannot agree withVan Deth's opinion (1946), according to which the pronephric duct developsin situ out of the dorsal parts of the lateral plate.

Expériences faites à Bruxelles, en avril 1947, grâce à une subvention de la « Nederlandse Commissie ter uitvoering van het Nederlands-Belgisch culturele verdrag ».  相似文献   

7.
Summary Diuron (DCMU) is inhibitory to the photoautotrophic and photoheterotrophic growth of the N2-fixing blue-green algaNostoc muscorum at concentrations of 1.0×10–5 M and 2.0×10–5 M, respectively. A mutant of this organism resistant to 5.0×10–5 M DCMU under its photoheterotrophic growth conditions, with the ability to utilize DCMU as a carbon and nitrogen source for growth, and complete inability to grow photoautotrophically has been isolated. With the apparent defect in its photosynthetic ability, it is suggested that theDCMU r mutant lacks the step inhibited by 1.0×10–5 M DCMU, and metabolizes DCMU by an existing enzyme system in the absence of such inhibition. That this enzyme may be glutamine synthetase (GS) is explained with the help of a L-methionine-DL-sulfoximine (MSO)-resistant mutant ofN. muscorum which is able to grow faster with 2.0×10–5 DCMU and is known to contain an altered GS.Thanks are due to the Council of Scientific and Industrial Research, CSIR Complex, Govt. of India, New Delhi-110012, for appointing the author to the Scientists' Pool for undertaking researches on the physiological and genetic controls of nitrogen metabolism in blue-green algae, a part of which is presented in this literature.  相似文献   

8.
Summary YG 19-256, 4-(1,3,4,9b-tetrahydro-5 methyl-2H-indeno[1,2-c]pyridine-2-yl)-2-butanone methane sulphonate, 1–3 mg/kg i.v., abolished or reduced photically-induced myoclonic responses for 1.5–6.5 h in baboons,Papio papio, without producing signs of acute neurological toxicity.We thank the Medical Research Council, The Wellcome Trust and the British Epilepsy Association for financial support, and Drs D.M. Loew and H. Weber (Sandoz Ltd) for the gift of YG 19-256.  相似文献   

9.
During the long eighteenth century, boundaries between theology and natural philosophy, between imaginary and factual travel narratives, between fiction and social commentary, were far more fluid than they are today. To explore these relationships, this paper links Mary Shelley’s Frankenstein—a book often hailed as the first science fiction novel—to two earlier works which are now less well known: Edmond Halley’s article about terrestrial magnetism, in which he suggested that God had created inhabited illuminated cavities inside the earth; and a satirical fantasy voyage written by the Danish author Ludvig Holberg, but published anonymously as Niels Klim’s journey to the underground and immediately translated into many languages. Attention is focussed on how the ambiguous presentation of these and other texts blurs any straightforward classification of genres. The aim of examining these writers together is not to search for direct mappings from one project to another, but instead to introduce Holberg’s unfamiliar yet important book and also to cast new light on Frankenstein, one of England’s most famous works of literature.  相似文献   

10.
Zusammenfassung An drei Kühen wurde um den Zeitpunkt der Geburt der Effekt eines spezifischen Prolaktininhibitors (2-Br--Ergokryptin-Methan-Sulfonat=CB-154, Sandoz, Basel) auf den Plasmaprolaktinspiegel und das Einsetzen der Laktation untersucht. In allen drei Fällen konnte eine starke Hemmung der Prolaktinbasiswerte als auch eine Unterdrückung des normalerweise vor der Geburt auftretenden Prolaktingipfels erreicht werden. Ebenfalls wurde die Laktation (vergleichsweise zum Vorjahr) eindeutig gehemmt. Maximal zeigte sich die relative Unterdrückung der Milchleistung bei der Kuh, welche kurz vor und auch noch nach der Geburt mit CB-154 behandelt wurde. Prolaktin wird somit für das Rind als das massgebliche Hormon der Laktogenese — im Gegensatz zur Galaktopoese — angesehen.

This wirk was supported by the Deutsche Forschungsgemeinschaft.  相似文献   

11.
Summary The author reviews a series of biological aspects of the study of oxygenable hematinoproteids, particularly with respect to evolution and adaptation. After a statement of some fundamental concepts of comparative biochemistry and of possible evolutionary relations between oxidation catalysts and oxygen carriers, the natural distribution of hemoglobins is reviewed and their specific characters are enumerated.A review is made of the data relating to the shape of the oxygen-dissociation curves and to the affinity of hæmoglobin for oxygen. It appears, generally speaking, that hyperbolic or almost hyperbolic curves and high affinity for oxygen are characteristic of primitive or embryonic hæmoglobins.A study of the function of hæmoglobin in the respiratory cycle of several animal species shows the vital importance of the oxygen carrier as well as the adaptation of the shape and position of the dissociation curve to the character of the respiratory function in the animal considered.The function of hæmoglobin in invertebrates, as oxygen carrier as well as providing a store of oxygen, is emphasized by a review of experimental data.The function of oxygen in the transport of carbon dioxide is reviewed from the standpoint of comparative biochemistry, and the lack of our knowledge is deplored.The characteristics of chlorocruorin show it to be a chemical mutation of an Annelid hæmoglobin.Our lack of knowledge in the field of the comparative biochemistry of hæmoglobin and chlorocruorin metabolism is pointed out.

Conférence principale, présentée à la Société suisse de biologie médicale lors de la 127e Assemblée générale de la Société helvétique des sciences naturelles à Genève, le 31 août 1947.  相似文献   

12.
Conclusion If the hundred years of study on theHensen's node — i.e. on gastrulation and early determination of the embryos of amniote vertebrates — teach anything, they teach in the first place how limited and fragmentary our knowledge is about one of the most central problems of the whole developmental biology. We know that the events in early amniote development — or early avian development, on which our data and ideas are nearly all based — in many ways resemble those in early Amphibian development, which is only slightly better understood, but we also know that direct extrapolations from anamniotes to amniotes cannot be made without proper reservations and without studying the amniote embryos themselves. And we have practically no idea of what is really going on in the cells of the blastoderm when they move, invaginate, induce or are induced, interact, become determined and begin their differentiation. We know that at the stages of gastrulation, the node, and indeed the whole blastoderm, is in a very labile state and can be regulated in many ways to produce a harmonious whole — or a monster — although we only understand very poorly the modes of this regulation. The progress made during the decades, and particularly in recent years, shows, however, that useful information is accumulating to produce a coherent picture, and there is no reason to be pessimistic.Dedicated to ProfessorEtienne Wolff on the occasion of his retirement.  相似文献   

13.
Zusammenfassung In ausgestanzten Blattstücken vonNicotiana tabacum, welche auf Wasser schwimmend inkubiert werden, findet im Verlauf von 7 Tagen ein beträchtlicher Abbau der Hemizellulose statt. Benzyladenin (10–5 M) verzögert den Abbau, Abscisinsäure (5×10–5 M) verstärkt ihn. Der Gehalt an Zellulose verändert sich im Verlauf der Alterung kaum.

The author is indebted to Dr.A. Artho and to theF. J. Burrus & Cie, Manufacture de Cigarettes, Boncourt, Switzerland, for generously supporting the present work. The skillful technical assistance of MissM. Schellenberg and the supply of abscisic acid by Hoffmann-La Roche, Basel, are gratefully acknowledged.  相似文献   

14.
Conclusions As in OspA-serotyping experiments, theB garinii group (OspA-sterotype 3–7) showed highest diversity within this internal fragment of p83/100, whereas theB. afzelii group (OspA-type 2) and theB. burgdorferi sensu stricto group (OspA-type 1) were nearly identical. Determination of the size of the PCR products as well as restriction fragment length polymorphism analysis (DraI) can be used for classification into the three species ofB. burgdorferi sensu lato. Since p83/100 is chromosomally encoded, this protein might be a more stable marker for classification than the plasmid-encoded OspA. In contrast to the flagellin gene a subclassification of theB. garinii group is possible due to the diversity of the p83/100 internal fragment.  相似文献   

15.
Summary Surviving muscle fibres of a molluscan smooth muscle (ABRM) in catch exhibit a characteristic pattern of longitudinal stripes when examined with theNomarski technique (Differential interference contrast). The pattern appears to be due to aggregated paramyosin-filaments; it disappears after abolishing the catch with 5-hydroxytryptamine or — in freeze-dried preparation — after raising the pH of the ATP-salt solution.  相似文献   

16.
    
Summary An account is given of the distribution of capsicidin — a saponin with antibiotic activity — inCapsicum annuum L., some conditions of its activity, and feeding experiments with rats.  相似文献   

17.
Planck's change in attitude to the question of whether atomic hypotheses were scientifically accessible, is discussed. It is argued contra Holton, that Planck's change in attitude to this question did not signal a methodological shift towards realism. The point of doing this is not just to investigate a significant episode in the history of quantum theory, but also to use the episode as a case study in support of a broader historical thesis. This thesis is that there was a widespread late-nineteenth century methodological tradition which motivated the change in status of certain ontological claims — e.g., that atoms exist — from ‘inaccessible to science’ to ‘scientifically acceptable’ even though those claims were not strictly ‘observable’. This methodological tradition is a hybrid of positivist and realist views. Thus, contrary to one popular view, the fin de siécle triumph of atomism is not to be seen as a triumph for a realist view of science Poincare's views are also used as an illustration.  相似文献   

18.
Zusammenfassung Ein Überblick über die angewandten Methoden zur Bestimmung der absoluten Konfiguration in Steroidseitenketten wurde gegeben. Die allgemeine Anwendung derR- undS-Regel wurde empfohlen.

In part, a summary of recommendations presented by the author to a National Academy of Sciences and National Research Councilad hoc Committee on Steroid Nomenclature (R. C. Elderfield, Chairman); October 13–15, 1961, Columbus (Ohio). The meeting of thead hoc committee was made possible by a grant from the U.S. Air Force Office of Scientific Research.

Part XV of a series entitledSteroid and Related Natural Products. Refer toG. R. Pettit andP. Hofer, Exper.19, 67 (1963), for the preceding contribution.  相似文献   

19.
Summary The chromosomal sets of five species ofPerlodidæ (Plecoptera) are given in the present paper. The sexual chromosomes belong to three distinct types:X-O,X 1-X 2,X 1-X 2-X 3. The author shows that these three types are likely derived from the most primitive patternX-Y, by translocation and inversion.  相似文献   

20.
Summary For the aromatic molecules benzene, naphthalene, and anthracene a relation is found between dipole moment and dissociation constant of the hydroxy compounds and the carboxylic acids on the one hand and the-electron density at the respective carbon atom in the unsubstituted molecule on the other hand. The following statement can be made:—The-electron density at a carbon atom of these aromatic systems is found to increase with its positive character. The effect is explained by using an electrostatic model.  相似文献   

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