Showing papers by "Aarhus University published in 1970"
TL;DR: A complex ecosystem of anaerobic and microaerobic properties underlies the oxidized surface layer of all marine sandy bottoms, with the exception of narrow “high-energy windows”.
Abstract: A complex ecosystem of anaerobic and microaerobic properties underlies the oxidized surface layer of all marine sandy bottoms, with the exception of narrow “high-energy windows”. Investigations made on both sides of the Atlantic Ocean, by T. Fenchel in Danish waters, and by R. Riedl and collaborators mainly in US (North Carolinian) waters; involve quantitative studies of plants, ciliates and invertebrates, measurements of chemical and physical parameters, systematics, physiological and model experiments.
518 citations
TL;DR: Fifty manic-depressive patients and thirty-four patients with recurrent endogenous depression who had been on open lithium treatment for at least a year took part in double-blind discontinuance studies to compare lithium carbonate and placebo.
433 citations
TL;DR: The distribution of the axons that arise in the fascia dentata and go to the hippocampus proper was investigated in this paper, where lesions were placed in the fimbria and degenerating mossy fibers were mapped by silver impregnation.
Abstract: The paper deals with the distribution of the axons that arise in the fascia dentata and go to the hippocampus proper. lesions were placed in the fascia dentata and degenerating mossy fibers were mapped by silver impregnation, mostly according to the method of Fink and Heimer ('67). The fascia dentata and the layer of mossy fibers in the rat form a curved and twisted structure extending from the level of the posterior aspect of the septum to the temporal tip. The horizontal serial sections used for this study were, therefore, in part interpreted by means of three-dimensional reconstructions.
Mossy fibers do not enter the fimbria at any point. Degenerating fibers can be traced to the limit between regio superior (CA 1) and regio inferior. This dentato-hippocampal connection displays a pattern of precise localization, each level of fascia dentata projecting onto a restricted level of regio inferior. The bands of degenerated mossy fibers produced by lesions in the fascia dentata were largely oriented in the transverse direction (slightly in a temporal direction) and were somewhat wider distally than at the origin from the hilus. Very narrow bands were seen in a few animals with particularly small lesions.
364 citations
TL;DR: In this paper, a compilation of coupling constants and low-energy parameters are given for pi N, KN, NN, YN, and meson-meson scattering, and a comparison of SU(3) comparison and predictions are discussed.
218 citations
TL;DR: Raised plasma-growth-hormone levels in juvenile diabetes, the persistence of abnormal G.H. response to exercise even in well-controlled diabetics, the inhibitory effect of hypophysectomy on the progression of diabetic retinopathy and the normalisation of skin capillary fragility after this operation all point to a role for G. H. hypersecretion in the development of diabetic angiopathy.
210 citations
TL;DR: In this article, muscle biopsies from sixteen diabetics were studied from sixteen juvenile, long-term diabetic patients. Most of the patients had severe retinopathy, but clinical signs of other forms of angiopathy and neuropathy were either absent or mild.
Abstract: Muscle biopsies were studied from sixteen juvenile, long-term diabetics. Most of the patients had severe retinopathy, but clinical signs of other forms of angiopathy and neuropathy were either absent or mild. The biopsies revealed severe degeneration, as well as ineffective regenerative changes of the terminal nerve fibres and endorgans.
184 citations
TL;DR: In this paper, a strong monad on a symmetric monoidal closed category with internal horn and | is shown to carry two canonical structures as a closed functor, in which case they are called strong monads.
Abstract: This note is concerned with "categories with internal horn and | and we shall use the terminology from the paper [2] by EIL~.NBERG and Kv.Imy. The result proved may be stated briefly as follows : a Y/--monad ("strong monad") on a symmetric monoidal closed category ~ carries two canonical structures as closed functor. If these agree (in which case we call the monad
179 citations
TL;DR: In this article, the authors studied the shape of C / R curves and in particular the optimum of C/R values depend strongly on the type and dimension of scintillators.
108 citations
TL;DR: In this article, a non-hermitian matrix problem for the time-dependent Hartree-Fock solution is reduced to a problem related only to hermitian matrices.
Abstract: Propagator or Green's function methods are used to analyze the time-dependent Hartree–Fock model The non-hermitian matrix problem for the time-dependent Hartree–Fock solution is reduced to a problem related only to hermitian matrices Particular attention is given to the calculation of oscillator strength in different approximations The connection between the stability of the Hartree–Fock solution and the solution of the time-dependent Hartree–Fock problem is demonstrated The results of numerical calculations are given for aniline, azulene and pyridine
97 citations
TL;DR: In this article, the authors derived approximate beta strength functions from measurements of the electroncapture beta feed to the high-lying excited states in about 40 neutron-deficient nuclei.
95 citations
TL;DR: The silver impregnation method of Fink and Heimer has been used on cryostat sections of both fresh frozen and formalin-fixed brain tissue mounted on slide and gave results comparable to those obtained on unmounted frozen sections of formal in-fixed material.
Abstract: The silver impregnation method of Fink and Heimer (Brain Res., 4: 369-74, 1967) has been used on cryostat sections of both fresh frozen and formalin-fixed brain tissue mounted on slide. The fixed brains were soaked in 25% sucrose for 2-3 days before freezing. The slides used for mounting were dipped in a 0.5% aqueous gelatin solution containing 50 mg of chrome-alum per 100 ml, drained and allowed to dry in a vertical position. Sections of fresh tissue were fixed for 16 hr in a 10% formalin solution buffered with phosphates to pH 7.0. Staining was carried out according to the Fink-Heimer procedure II and gave results comparable to those obtained on unmounted frozen sections of formalin-fixed material
TL;DR: In the intact contractile apparatus, myosin is present in very long ribbon-like structures and actin exists in the usual filaments but these are here arranged in small regular arrays between and around theMyosin ribbons.
Abstract: In the intact contractile apparatus, myosin is present in very long ribbon-like structures Actin exists in the usual filaments but these are here arranged in small regular arrays between and around the myosin ribbons
TL;DR: In this paper, the equilibrium charge fractions have been measured for beams of N, O, F, Ne, Na, Mg, Al, and Ar in the energy range from 100 to 500 keV.
TL;DR: Evidence from X-ray diffraction studies is presented suggesting that in living relaxed vertebrate smooth muscle myosin is present in the form of filaments.
Abstract: THE sliding filament mechanism for muscular contraction was first established in the case of vertebrate striated muscle1,2. Shortly afterwards good evidence for the existence of a similar mechanism was obtained in a molluscan smooth muscle3. Attempts to explain contraction in vertebrate smooth muscle, however, met with considerable difficulties, mainly because of uncertainty about the state of myosin in the living relaxed muscle. This still cannot be decided from the biochemical4–6, electron optical7–16 and X-ray diffraction17–19 evidence available so far. Here we present evidence from X-ray diffraction studies suggesting that in living relaxed vertebrate smooth muscle myosin is present in the form of filaments.
TL;DR: In this article, an integral equation for the pair correlation function, coupling the individual ion range with the deposited energy, was established to determine the damage caused by all those ions that come to rest at a specific penetration depth.
Abstract: Simple depth distribution functions of ion bombardment damage predict the spatial extension of the cumulative damage caused by a beam of ions. Correlation functions need to be considered when more detailed information is desirable, such as the average size or depth of individual damage clusters, the average location of an ion within its damage cluster, and the fluctuations of these quantities. In this paper we establish an integral equation for the pair correlation function, coupling the individual ion range with the deposited energy. This pair correlation function determines the damage caused by all those ions that come to rest at a specific penetration depth. Solutions of the integral equation are found by standard methods. Explicit results are presented for elastic scattering governed by power cross sections. The depth distribution of damage clusters turns out to be significantly narrower than the gross damage distribution at all mass ratios except for M 1 ≪ M 2, and the size distribution appe...
TL;DR: In this article, the beamfoil excitation technique has been used to measure mean-lives of excited atomic states in MgI, MgII, CaI, and CaII.
Abstract: The beam-foil excitation technique has been used to measure mean-lives of excited atomic states in MgI, MgII, CaI, and CaII. The mean-lives of the 3p 1P° states in MgI and the 4p 1P° state in CaI have been measured to be 2.2±0.2×10-9 sec and 6.2±0.5×10-9 sec, respectively. The discrepancies with some of the earlier published data for CaI have been attributed to the anomalously high cross section for broadening of the resonance line. For some of the doublets in MgII and CaII, mean-lives have been obtained for both transitions of the doublets, and the intensity ratios have been checked. Oscillator strengths have been evaluated and compared with theoretical predictions.
TL;DR: Stapedius-muscle-reflex examinations were performed on two patients shown to have brain stem tumours and an apparatus of the type mentioned above is valuable in the diagnosis and localization of brain stem affections and in the further in vestigation of the stapedius muscle reflex arch.
Abstract: Stapedius-muscle-reflex examinations were performed on two patients shown to have brain stem tumours. The reflexes were tested with an impedance-measuring device capable of measuring the stapedius reflexes not only by contralateral stimulation but with homolateral stimulations as well. In these patients, the contralateral stimulation produced no response, while homolateral stimulation resulted in normal reactions. These indications can only be explained by an interruption of the reflex arch of the stapedius muscle at a point within the brain stem, between the cochlear nuclei on the one side and the facial nucleus on the other side. An apparatus of the type mentioned above is valuable in the diagnosis and localization of brain stem affections and in the further in vestigation of the stapedius muscle reflex arch.
TL;DR: Th Thin sections tangential to the nuclear envelope, described in this paper, reveal directly the degree of order within the surface layer; there are small areas or patches in which the units are regularly arranged.
Abstract: A unit thread has been identified by electron microscopy as the common structural element in the condensed chromatin of a variety of cell nuclei. From the previous studies of thin sections normal to the nuclear envelope it was concluded that the unit thread, of diameter about 17 nm but varying somewhat depending on fixation, packed with spacings of about 28 nm on the surface of the nucleus to form one or more layers. Thin sections tangential to the nuclear envelope, described in this paper, reveal directly the degree of order within the surface layer; there are small areas or patches in which the units are regularly arranged. Units are also orderly arranged around the pores in the nuclear envelope. Unit threads are less easily visible in electron micrographs of mature erythrocytes than at earlier stages of development but the clarity with which they can be seen is increased by a brief treatment prior to fixation with sodium citrate.
TL;DR: A model for the paramyosin filaments of molluscan adductor muscles is proposed to account for features of the X-ray diffraction patterns and electron micrographs of these muscles, which shows a characteristic pattern when subjected to a process which reveals depressions in the surface and which is somewhat analogous to negative staining.
TL;DR: In this paper, a geometric construction is used to find the matrix representation of the two-particle Green function for a pi-electron model of ethylene, and a self-consistency condition is derived, allowing calculation of highly accurate values for the bond order, ionic character and elementary excitations.
TL;DR: In this article, photolysis of aryliodides in the presence of t -nitrosobutane gave aromatic nitroxide radicals, the spectra of which were analyzed.
Book•
01 Jan 1970TL;DR: This is a completely revised and updated edition of this text designed to introduce students to the historical, intellectual and social context of computers.
Abstract: This is a completely revised and updated edition of this text designed to introduce students to the historical, intellectual and social context of computers Although the majority of the chapters in this edition are new, the original criteria for selecting essays has been retained The text retains the historical pieces and adds new material on artifical intelligence, the human-computer interface, the intellectual importance of computing, and the social imapct of computer technology
TL;DR: The two central fibers of the axoneme of the human sperm tail are interconnected by regularly spaced ribs, which are perpendicular to the longitudinal axis of the fibers.
TL;DR: Comparison of the weights of field and laboratory reared animals indicates that they consume similar amounts of food during development, and the number of sycamore aphids required for development in the field is estimated, and it is suggested that under natural conditions, thenumber of anthocorids which reach maturity is dependent upon the numberof young aphids available during the early stages of the anthocOrids’ development.
Abstract: Laboratory observations on the searching behaviour and efficiency of the anthocorids Anthocoris conjusus and A. nemorum in capturing the sycamore aphid led to the suggestion that the anthocorids would be unable to survive on sycamore trees unless the population density of young aphids on the leaves exceeded a certain value. This value is 14 and 5 small aphids per 10 dm2 of leaf, for A. confusus and A. nemorum respectively.
Analysis of observations on the incidence of predation by anthocorids on the sycamore aphid confirms that the number of anthocorid nymphs appearing on sycamore in the spring is related to the number of young aphids present. However, it is the numbers of parasitized aphids and adult aphids present in June and July that determine the proportion of the anthocorid nymphs that become adult. Despite their ability to avoid capture, adult aphids are so abundant in some years that this more than compensates for the anthocorids' inefficiency in capturing them.
The proportion of the sycamore aphid population killed by the anthocorids in the field decreases as the sycamore aphid increases in abundance.
ZUSAMMENFASSUNG
DIE WIRKSAMKEIT VON ANTHOCORIS NEMORUM UND A. CONFUSUS (HEMIPTERA: ANTHOCORIDAE) ALS PRADATOREN DER AHORNBLATTLAUS, DREPANOSIPHUM PLATANOIDES. II. SUCHVERHALTEN UND DIE RAUBERWIRKUNG IM FREILAND.
Uber das Suchverhalten und die Wirksamkeit der Anthocoriden Anthocoris confusus und A. nemorum bei der Erbeutung von Ahornblattlausen wurden Laborbeobachtungen durchgefuhrt. Kombination der Ergebnisse mit Befunden uber die Nahrungsbedurfnisse der Anthocoriden (Russel, 1970) ermoglichten dann Schatzungen uber die Populationsdichte der Blattlause, die fur die erfolgreiche Entwicklung der Anthocoriden erforderlich ist. Die benotigten Werte betragen fur A. confusus 14 und fur A. nemorum 5 kleine Blattlause pro 10dm2 Blattflache.
Eine Analyse von Beobachtungen uber das Auftreten der Erbeutung von Ahornlausen durch die Anthocoriden bestatigt, das die Anzahl der im Fruhjahr an Ahorn auftretenden Anthocoriden-Larven in Beziehung zur Anzahl der vorhandenen jungen Blattlause steht. Jedoch bestimmt die Anzahl der parasitierten sowie der erwachsenen Blattlause, die im Juni und Juli vorhanden sind, den Anteil der Anthocoriden-Larven, der das Adultstadium erreicht. Trotz der Fahigkeit der Ahornlause, der Erbeutung zu entgehen, wird in manchen Jahren die schlechte Fahigkeit der Anthocoriden, sie zu erbeuten, durch die Haufigkeit der Blattlause mehr als ausgeglichen.
Das Verhaltnis der von den Anthocoriden im Freiland getoteten Ahornlause nimmt in dem Mase ab, wie die Haufigkeit der Ahornlause zunimmt.
TL;DR: Muscle biopsies from eight cases of acute juvenile diabetes revealed well marked degenerative changes combined with vigorous regeneration of the terminal neuromuscular apparatus in a few weeks after the beginning of the disease.
Abstract: Muscle biopsies from eight cases of acute juvenile diabetes (a few weeks after the beginning of the disease) revealed well marked degenerative changes combined with vigorous regeneration of the terminal neuromuscular apparatus. This observation is in accordance with previous demonstrations of neurophysiological disturbances at this early stage of diabetes.
TL;DR: In this article, the authors describe the mechanics of certain types of operations on rings (e.g. A-operations on special A-rings or differentiation operators on rings with derivation).
Abstract: Introduction The main aim of this article is to describe the mechanics of certain types of operations on rings (e.g. A-operations on special A-rings or differentiation operators on rings with derivation). En route we meet the very useful notion of a representable functor from rings to rings. If B, R are rings, then the set Hom^(J5,i2) of ring homomorphisms does not, in general, have a ring structure (unlike, for instance, the case where G, H are abelian groups, in which case Homg(G,H) is naturally an abelian group). However, we shall show in § 1 that, if B also has a 'co-ring' structure (in which case we call it a hiring) then this induces a natural ring structure on Homg?(J5,i2). In this case, the functor R \\-> Hom^jB, R) is said to be represented by the biring B. In §2, we demonstrate that this functor has a left adjoint, which we denote by R h-» B © R to bring out the analogy with the abelian group case (where H h» G® H is left adjoint to H h> Homg((r,fi)). When, in §4, we come to discuss natural operations on a certain class of rings, there are many constructions we may perform. Given a collection T of operations on a ring, we may give T a ring structure by addition and multiplication of the values of operations. We are also interested in the value of an operation on the sum and product of two elements in terms of its value on those elements. This may be given by imposing a co-ring structure on T in which, for example, the effect of an operation on the sum of two elements is determined by the co-sum' of that operation on the tensor product of the elements. Finally, given two operations on a ring, we may form the composite of one followed by the other. We insist that the identity operation is in T. All these requirements add up to the notion of a 'biring triple' in § 3. In § 4 we discuss the class of rings on which the operations in T act and in §§5, 6 we concentrate on the particular examples afforded by special A-rings and rings with derivation. There follow three appendices which contain material supplementary to that in the main text which would otherwise have interrupted the flow of the exposition.
TL;DR: In this article, the electrolysis of N-heterocyclic compounds is discussed and the polarographic results are provided to supplement the discussion and to suggest further use of preparative electrolysis.
Abstract: Publisher Summary This chapter discusses the electrolysis of N-heterocyclic compounds and emphasizes on preparative electrolysis. The polarographic results are provided to supplement the discussion and to suggest further use of preparative electrolysis. The chapter focusses on electrolysis at a controlled potential. The electrolysis of an organic compound involves one or more steps in which electrons are transferred to or from the electrode and some chemical steps before and/or after the electrochemical steps. Electrode reactions may be divided into two main types depending on whether the electron transfer occurs directly between the electrode and the substrate or whether the electron is transferred to (or from) another species, which then reacts with the substrate. The apparatus for electrolysis requires electrodes, cells and circuits. The electrolytic formation of heterocyclic systems involves ring closure reactions, ring contractions, and ring expansions. The electrode reactions of heterocyclic compounds where a reduction or oxidation of the nucleus takes place are discussed. The electrolysis of substituted heterocyclic compounds, where the electrode reaction involves the substituent directly or when it plays an essential role in determining the course of the reaction and the reductions leading to ring contractions has been described.
TL;DR: In this paper, the beam-foil excitation technique has been used to measure mean lives of excited atomic states in Na i, Na ii, Na iii, K ii, and K iii.
Abstract: The beam-foil excitation technique has been used to measure mean lives of excited atomic states in Na i, Na ii, Na iii, K ii, and K iii. In agreement with earlier measurements, a mean life of 17.3±1.0×10−9 s has been obtained for the unresolved 3s–3p doublet transition in Na i. The mean lives of the 3p5 4p fine-structure levels in K ii have been measured and compared with earlier measurements in Ar i. Based on the observed mean lives, two spectral lines (2387 and 2394 A), previously assigned as Na ii lines, have been assigned as transitions in Na iii.