Paul Ehrenfest on the Necessity of Quanta (1911): Discontinuity,Quantization, Corpuscularity,and Adiabatic Invariance

Our object in this paper is to study the antecedents, contents, implications, and impact of a not well-known or appreciated paper by EHRENFEST in 1911 on the essential nature of the different quantum hypotheses in radiation theory. After a careful analysis of EHRENFESTs notebooks, correspondence, and publications, we conclude that the essential points of EHRENFESTs paper were not perceived to a large extent, and hence that its implications were not considered thoroughly. Specifically, we show that EHRENFEST contributed significantly to the clarifications of the differences between PLANCKs and EINSTEINs respective quantum hypotheses, as well as to those of the concepts discontinuity, quantization, and corpuscularity.     

Molecular ecology of a Neolithic meadow: The DNA of the grass remains from the archaeological site of the Tyrolean Iceman

The paper reports on the molecular analysis of samples of approximately 5,300-year-old grass found at the alpine archaeological site where the so-called Tyrolean Iceman was discovered. The grass comes from a cloak made of long grass blades and/or the stuffing of the snow footwear worn by the Iceman. The results show that while the largest fraction of the DNA extractable from the grass is of foreign origin, a much smaller part belongs to the original genetic material of the grass itself, and can be used as a valuable taxonomic clue to the plant species utilized by neolithic men to manufacture their equipment. On the other hand, the foreign DNA, or at least a portion of it, comes from microorganisms-mainly filamentous fungi and unicellular algae-which seem to have been associated with the grass since the time the grass was harvested.     

Mass spectrometric determination of the amino acid sequence in peptides: Desulfurization of sulfur-containing peptides

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Über das Vorkommen verschieden substituierter Chalkone während der Mikrosporogenese beiTulipa

Summary During the development of anthers inTulipa cv. Apeldoorn the following chalcones were isolated: 2, 3, 4, 4, 6-pentahydroxychalcone as the main component and 2, 4, 4, 6-tetrahydroxy-3-methoxychalcone as well as 2, 4, 4, 6-tetrahydroxychalcone in a very small amount.

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Die Untersuchungen wurden mit Mitteln der Deutschen Forschungsgemeinschaft unterstützt.     

IdentifyingY chromosome in interphase nuclei of the human brain

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Correlations between glucose-inhibition and control parameters of α-glucosidase kinetics inApis mellifica haemolymph (Hymenoptera: Insecta)

Summary Kinetics studies of haemolymph -glucosidase inhibition by D. glucose led to general correlations between inhibition and control parameters, all over the honeybee development. Maximum velocities are not affected by the inhibition, while affinity constants are always significantly increased, and Hill coefficients tend to decrease, especially in foraging adults and in prenymphs. In this later case, the n-type effect tends to break the manifestation of the K-type mechanism.     

Circadian periodicity in termination of photorefractoriness in the yellow-throated sparrow

Summary Photorefractory male yellow-throated sparrows (Gymnorhis xanthocollis) were subjected to six resonance light cycles, consisting of 6 h basic photophase coupled with scotophases of longer durations (in cycles of 12 (6L6D) h, 24 (6L18D) h, 36 (6L30D) h, 48 (6L42D) h, 60 (6L54D) h and 72 (6L66D) h). Termination of photorefractoriness was evident in cycles of 24, 48 and 72 h, but not in 12, 36 and 60 h. The results are consistent with the external-coincidence model (Bünning hypothesis) and suggest that endogenous circadian rhythmicity is involved in the termination of photorefractoriness.To whom reprint requests should be addressed.This investigation was supported by a UGC grant to PDT and BHU to PMT.     

Axillary 5α-androst-16-en-3-one in men and women: Relationships with olfactory acuity to odorous 16-androstenes

Summary Axillary 5-androst-16-en-3-one (5-androstenone) levels were found to be significantly higher in men than in women but do not vary between left and right axillae, are not related to age, handedness or degree of hirsutism (in women) nor to anosmia to this steroid. In men (but not in women), levels are related linearly to axillary cholesterol concentrations but not to squalene. Olfactory thresholds for 5-androstenone varied widely, the lowest recorded being 0.2 ppb, but there was no difference in thresholds between men and women. Women (70%) found the smell repellant but anosmia did not differ greatly between men and women (9–20%). Anosmia to the smell of 5-androst-16-en-3-ol was most marked in women (90%) rather than in men (45%). Axillary 5-androstenone values were generally consistent with the musky or strong smells of male axillary extracts, compared with the sweet smell of those from female subjects.Supported by the Herbert Dunhill Trust.     

On the host-symbiont-cycle of a leafhopper (Euscelis plebejus) endosymbiosis

Summary In the host-symbiont-cycle ofEuscelis plebejus and its bacterial symbionts each of both symbionts (a and t) appears in an infection form during the intraovarial transmission (adult female) as well as during the entrance into the mycetocytes (embryo) and in a vegetative form during the remaining time of the cycle.This work was supported in part by a grant from the Deutsche Forschungsgemeinschaft to ProfessorK. Sander, whom I thank for helpful discussions.     

Isoforms of baker's yeast transketolase

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Changes in the lumen of coronary vessels under oligemic hypotension

Conclusions The decrease of circulating blood volume, resulting in oligemic hypotension, may evoke in anaesthetized cat the active constrictory coronary vessel responses of 2 types, one occuring immediately after start of the hypotension and the other having a significantly prolonged latency.

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The role of the pentose-phosphate pathway in adjustment of the heart to a high load and the development of myocardial hypertrophy

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Chromosomes and giemsa-bands of the Idaho spotted ground squirrel,Spermophilus brunneus (Howell)

-Spermophilus brunneus . , 13 18 ,S. brunneus S. townsendii mollis (2n=38) , , ; ;S. brunneus . S. brunneus , Spermophilus.

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Supported by National Science Foundation Grants No. GB32114X and No. GB 29131X, and the Sprague Foundation. We thankD. Pozin for technical assistance.     

Free radicals and aflatoxin biosynthesis

Summary The addition of some halogenated alkanes (bromotrichloromethane, carbontetrachloride and chloroform) to cultures ofA. parasiticus andA. flavus have shown a high stimulating effect on aflatoxin biosynthesis. When the production of aflatoxin increases during the stimulating effect the peroxidase activity is inhibited.Acknowledgments. Supported by Cassa di Risparmio di Roma, funds from Ministry of Education and Faculty of Science of La Sapienza Rome University.     

Determinant of efficiency of a monomeric enzyme: Acceleration by site-specific molecules for trypsin

Summary The interaction of a specific ligand at substrate binding site was shown to be responsible for the catalytic efficiency of trypsin. The reasoning of induced fit theory was refined by kinetic analysis of characteristic properties of inverse substrates.This work was supported by grants from the Ministry of Education, Science and Culture, Japan.     

Temperature sensitivity in the respiratory-deficient mutants of yeast (Saccharomyces cerevisiae)

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Conjugated terpenoid ketones: A new group of plant growth regulators

Summary ,-unsaturated terpenoid ketones have a root-inducing property on the hypocotyl cuttings ofPhaseoulus aureus. Significantly isopathcoulenone, (I) is distinctly more active in causeing rooting over IAA.Acknowledgment. The work was financially supported by the Punjab State Government, India, under the scheme Chemistry of some natural products and their significance in agriculture. The authors thank Dragoco, Holzminden, Federal Republic of Germany, for supplying the samples of monoterpenes.     

The detection of fraud and fakery

Summary Fraud is often found in science, especially in what is termed, fringe science. There are several reasons why scientists should be aware of the fact that they, too, can be deceived, both by subjects in experiments and by themselves. The will to believe is strong even among hard-headed academics, and is often the factor that causes them to publish results that do not stand up to subsequent examination and/or attempts to replicate. In some cases, scientists would be well advised to consult with such experts as conjurors, when skilled frauds are in a position to mislead them.     

On the origin of the protein yolk in the oocytes ofAplysia depilans (Gastropoda,Opistobranchia)

Summary In the oocytes ofAplysia depilans it has been observed electronmicroscopically that gemmae or daughter-nucleoli separate from the nucleolus. These gemmae after having overcome the nuclear membrane, would aggregate together, even after transformation, into yolk globules. These observations seem to give plausibility to the hypothesis that there is a close relationship between production of ribonucleoproteic material by the nucleolus and yolk production.     

Nature and the time course of the effect of CO2 on electroretinogram (ERG) in an arachnid

Summary Electroretinogram recorded from the median eye of the scorpion, Heterometrus fulvipes before and after exposure to CO₂ indicated that the rate of recovery of b wave to pre-CO₂ level was slow and delayed as compared to a wave. b wave may therefore have a more central origin than that of a wave, which finds corroboration in the results of the depth recording in this eye with the microelectrode.The equipment was a gift from USAFOSR to Prof. T. H. Bullock and Prof. K. P. Rao, and the work was carried out at the Department of Zoology, Bangalore University. I thank Dr R. V. Krishnamoorthy and Dr A. R. Kasturi Bai.