Effects of high gravity on amoebae (Pelomyxa carolinensis). I. Division rates

Zusammenfassung Amöben (Pelomyxa carolinensis), die einem Gravitationsstress von 10 bis 54 g/h ausgesetzt wurden, waren in ihrer Teilungsrate signifikant behindert.

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We wish to acknowledge the National Aeronautics and Space Administration, USA for support of this study.     

Antimitotic agents and macronuclear division of ciliates. III. The effect of colchicine on synchronizedTetrahymena pyriformis GL

Zusammenfassung Durch Temperaturschocks synchronisierte Kulturen des CiliatenTetrahymena pyriformis (Stamm GL, kein Mikronucleus) wurden mit Colchicin behandelt. In Abhängigkeit vom Zeitpunkt der Colchicinzugabe wurden Verzögerungen des ersten synchronisierten Teilungsmaximums festgestellt. Die Ergebnisse werden als weitere Hinweise auf eine Beteiligung von Mikrotubuli bei der Makronucleus-Teilung gedeutet.     

Physiological studies on the effects of nutritional imbalance on the central nervous system. II. Effects of thiamine deficiency on oxidative enzymes in the brain of chicken, Gallus domesticus.

The activitiy levels of succinate dehydrogenase, glutamate dehydrogenase and pyruvate dehydrogenase in the fore, mid and hind brain regions of the thiamine deficient chicken, Gallus domesticus were determined. The activity levels of succinate dehydrogenase and glutamate dehydrogenase in all the 3 regions of brain showed augmentation on inducing thiamine deficiency. In contrast the activity levels of pyruvate dehydrogenase decreased in the brain of thiamine deficient animals. It is suggested that these changes in the oxidative enzymes indicate disturbance caused in the operation of the tricarboxylic acid cycle in thiamine deficiency.     

Localization and the interface between quantum mechanics, quantum field theory and quantum gravity II: The search of the interface between QFT and QG

The main topics of this second part of a two-part essay are some consequences of the phenomenon of vacuum polarization as the most important physical manifestation of modular localization. Besides philosophically unexpected consequences, it has led to a new constructive “outside-inwards approach” in which the pointlike fields and the compactly localized operator algebras which they generate only appear from intersecting much simpler algebras localized in noncompact wedge regions whose generators have extremely mild almost free field behavior.Another consequence of vacuum polarization presented in this essay is the localization entropy near a causal horizon which follows a logarithmically modified area law in which a dimensionless area (the area divided by the square of dR where dR is the thickness of a light-sheet) appears. There are arguments that this logarithmically modified area law corresponds to the volume law of the standard heat bath thermal behavior. We also explain the symmetry enhancing effect of holographic projections onto the causal horizon of a region and show that the resulting infinite dimensional symmetry groups contain the Bondi–Metzner–Sachs group. This essay is the second part of a partitioned longer paper.     

Biosynthesis and roles of phospholipids in mitochondrial fusion,division and mitophagy

Mitochondria move, fuse and divide in cells. The dynamic behavior of mitochondria is central to the control of their structure and function. Three conserved mitochondrial dynamin-related GTPases (i.e., mitofusin, Opa1 and Drp1 in mammals and Fzo1, Mgm1 and Dnm1 in yeast) mediate mitochondrial fusion and division. In addition to dynamins, recent studies demonstrated that phospholipids in mitochondria also play key roles in mitochondrial dynamics by interacting with dynamin GTPases and by directly changing the biophysical properties of the mitochondrial membranes. Changes in phospholipid composition also promote mitophagy, which is a selective mitochondrial degradation process that is mechanistically coupled to mitochondrial division. In this review, we will discuss the biogenesis and function of mitochondrial phospholipids.     

Effects of selective intracranial section and stimulation of vago-accessory roots II. Efferent cardio-inhibitory fibers

Riassunto Fibre cardio-inibitrici sono contenute non solo nella radice del X^o nervo, ma anche nella radice bulbare dell'accessorio, seppure in grado minore. Mentre nel preparato normale le fibre cardio-inibitrici dell'accessorio non sembrano prendere parte al mantenimento del cosidetto « tono vagale », nell'animale decerebrato sono responsabili, almeno in parte, del notevole grado di bradicardia che caraterizza questo preparato.     

Effects of selective intracranial section and stimulation of vago-accessory roots II. Efferent cardio-inhibitory fibers

Riassunto Le radici bulbare e spinale del nervo accessorio non contengono fibre afferenti provenienti dal territorio polmonare e dall'area aortica. Queste entrano nel bulbo esclusivamente con la radice del nervo vago. Le cellule gangliari contenute nelle radici dell'accessorio sono probabilmente in relazione con il controllo propriocettivo dei muscoli striati innervati dai rami esterno (spinale) ed interno (bulbare) di questo nervo.     

Adrenergic innervation of the male reproductive ducts in some mammals. II. Effects of vasectomy and castration

Résumé Après vasectomie complète, pratiquée sur des rats, la fluorescence des terminaisons nervcuses, ainsi que la substance transmettrice, disparaît le long du canal déférent et de l'extrémité de l'épididyme en deçà de la lésion. Chez les chats, les terminaisons nerveuses dans les canalicules efférents et la tête de l'épididyme ne disparaissent pas après l'opération. Dans la direction de la glande et du ganglion prostatique, la matière fluorescente s'accumule dans les troncs nerveux, et les terminaisons nerveuses restent visibles. Après castration, quelques modifications compensatrices ont été observées.     

Physiological studies on the effects of nutritional imbalance on the central nervous system. II. Effects of thiamine deficiency on oxidative enzymes in the brain of chicken,Gallus domesticus

Summary The activity levels of succinate dehydrogenase, glutamate dehydrogenase and pyruvate dehydrogenase in the fore, mid and hind brain regions of the thiamine deficient chicken,Gallus domesticus were determined. The activity levels of scccinate dehydrogenase and glutamate dehydrogenase in all the 3 regions of brain showed augmentation on inducing thiamine deficiency. In contrast the activity levels of pyruvate dehydrogenase decreased in the brain of thiamine deficient animals. It is suggested that these changes in the oxidative enzymes indicate disturbance caused in the operation of the tricarboxylic acid cycle in thiamine deficiency.     

The cosmological constant, the fate of the universe, unimodular gravity, and all that

The cosmological constant is back. Several lines of evidence point to the conclusion that either there is a positive cosmological constant or else the universe is filled with a strange form of matter (“quintessence”) that mimics some of the effects of a positive lambda. This paper investigates the implications of the former possibility. Two senses in which the cosmological constant can be a constant are distinguished: the capital Λ sense in which lambda is a universal constant on a par with the charge of the electron, and the lower case λ sense in which lambda is a humble constant of integration. The latter interpretation has been touted as the means to a solution to various problems in physics. These claims are critically examined with an eye to discerning the implications for philosophy of science and foundations of physics.