Showing papers by "University of Kiel published in 1976"
TL;DR: In this article, a stuffed tridymite structure of CaAl 2 O 4 was re-examined by single crystal X-ray data and the orientation of the tetrahedrals in this tridyclic structure was discussed in comparison with other known compounds.
203 citations
TL;DR: In this article, the effect of light intensity on rate of photosynthesis was measured at irregular intervals over a 12-month period for 22 benthic marine algae in the western Baltic Sea.
Abstract: The effect of light intensity on rate of photosynthesis was measured at irregular intervals over a 12-month period for 22 benthic marine algae in the western Baltic Sea. In most species photosynthesis (mg O2·g dry weight-1·h-1) was highest in spring and summer, corresponding to the seasonal growth pattern of the algae. In winter all the species showed adaptation of the light compensation point. Highest productivity was shown by algae which are: short-lived annual species rather than perennials, eulittoral rather than sublittoral, and which possess sheet-like or filamentous thalli rather than coarsely branched forms. These factors are clearly inter-related.
195 citations
TL;DR: It is concluded from the results that the fraction of very small heterotrophic bacteria which cannot be cultured on nutrient media is responsible for the continuous breakdown of organic matter in off-shore regions of the sea.
Abstract: Substrate transformation and microbial biomass production in aquatic ecosystems depend mainly on the total number of actively metabolizing heterotrophic bacteria. The most common methods used concern the determination of either the colony-forming bacteria or the total number of bacteria including autotrophs and inactive organisms a micro-autoradiographic method is presented which enables the substrate uptake of single bacteria by means of 3H-amino-acid mixture and Nuclepore filters to be determined. The standardization procedure revealed the greatest success after 3 h incubation with 10 μCi/ml tritiated amino-acid mixture and an exposure of 14 days to the X-ray film. Preliminary experiments showed inactivation of an active fresh-water population from 100% to 0.6% within 3 h at 28‰S. With increasing distance from the shore, the number of colony-forming units decreases from 6 to 0.01% of the total number of active heterotrophic bacteria. It is concluded from the results that the fraction of very small heterotrophic bacteria which cannot be cultured on nutrient media is responsible for the continuous breakdown of organic matter in off-shore regions of the sea.
189 citations
TL;DR: Five lymphatic neoplasms with strong focal acid phosphatase reactivity were selected from a group of acute lymphocytic leukemias and lymphoblastic lymphomas and it was found that a considerable number of tumor cells in all five cases formed mixed rosettes, i.e. that they bore the C3 receptor characteristic of B cells and simultaneously the E receptors characteristic of T cells.
Abstract: Five lymphatic neoplasms with strong focal acid phosphatase reactivity were selected from a group of acute lymphocytic leukemias and lymphoblastic lymphomas. All five cases showed an anterior mediastinal mass and exhibited identical morphology. This type of lymphoma has been described by Lukes under the term "malignant lymphoma of convoluted lymphocytes". Analysis of surface membrane receptors revealed that the tumor cells lacked surface immunoglobulin and receptors for Fc-fragment, but possessed receptors for complement (C3), untreated SRBC (ES) and SRBC treated with neuraminidase (ESN). By applying a mixed rosette assay using nucleated chicken erythrocytes coated with antibodies and C3, and denucleated ESN, it was found that a considerable number of tumor cells in all five cases formed mixed rosettes, i.e. that they bore the C3 receptor characteristic of B cells and simultaneously the E receptor characteristic of T cells. Thus the tumor cells resembled immature thymocytes of 10-15 weeks' gestation, which also show focal acid phosphatase reactivity and simultaneous expression of C3 and E receptors.
157 citations
TL;DR: Neither direction nor amplitude ofIK but only the pulse potential seems to determine the extent of block for a given [4-AP], even ifIK is additionally but temporarily suppressed by tetraethylammonium.
Abstract: 1. Voltage clamp experiments were done on single myelinated nerve fibres of the frog, Rana esculenta. 2. 53 muM 4-aminopyridine (4-AP) reduced IK to about one-fifth if tested with infrequent (1/min) and short (10 ms) depolarizing pulses; the onset time constant under these circumstances was ca. 160 s (14-15 degrees C). After prolonged treatment the effect was virtually irreversible. 3. At equilibrium with 4-AP, increasing the frequency of short pulses removed part of the block, the block removal accelerating with increasing pulse duration and frequency. 4. In 53 muM 4-AP unblocking of K channels during long (0.8 s) depolarizing pulses proceeded with a time constant, taur, of ca. 0.2 s. Restoration of block at the resting potential proceeded with a much larger time constant, tau'r, of ca. 1 min. 5. The stationary fraction, rinfinity, of K channels conducting in 53 muM 4-AP was 0.66, 0.41, and 0.24 at V = 120, 50, and 0 mV, respectively. 6. In a series of experiments with [4-AP] varying between 13.3 and 848 muM, taur decreased from 0.25 to 0.10 s (V = 130 mV, ca. 17 degrees C) while rinfinity followed the empirical relation 1/rinfinity = 1 + ct + cv exp(-0.77 EF/RT) with E = V - 70 mV. ct and cv are dimensionless quantities that increase with [4-AP] and reflect the voltage-independent and voltage-dependent component, respectively, of block. 7. Block of K channels and partial removal are also observed with inward IK at raised [K+]O. Removal proceeds on depolarization even if IK is additionally but temporarily suppressed by tetraethylammonium. Hence neither direction nor amplitude of IK but only the pulse potential seems to determine the extent of block for a given [4-AP].
126 citations
TL;DR: Viking 2 lander began imaging the surface of Mars at Utopia Planitia on 3 September 1976, finding a boulder-strewn reddish desert cut by troughs that probably form a polygonal network.
Abstract: Imagery of the surface of Mars obtained by Viking 1 is analyzed. The lander is situated on the western slopes of the 5-km deep Chryse Planitia depression, about 2 km higher than the floor. The topography is gently rolling. Angular rocks and small sand dunes are visible. There are very few craters; initial evaluations indicate that crater area densities are several orders of magnitude below saturation for crater sizes less than about 50 m. The presence of scour marks and of fine-grained deposits in some boulders indicates that some aeolian activity has occurred. Almost all the sky brightness can be attributed to scattering by particles present in the atmosphere. No signs of movement have been detected, consistent with the low seasonal winds recorded by meteorological instruments.
123 citations
TL;DR: NMR binding measurements have been performed in order to analyze the molecular mechanism underlying the drug-induced phospholipidosis, and increasing lipophilicity is correlated with an increase in binding for this type of amphiphilic drugs.
109 citations
TL;DR: In this paper, hot-wire anemometer measurements have been made in a dilute sea-water/claymineral suspension and the results indicated that turbulent-drag reduction occurs for the experimental clay-mineral suspensions at non-eroding and also at eroding velocities.
Abstract: Hot-wire anemometer measurements have been made in a dilute sea-water/claymineral suspension. For fully developed turbulent flows in an open channel with a smooth mud (from the North Sea) bottom, mean streamwise velocity profiles were measured for Reynolds numbers between 5400 and 27 800 (i.e. non-eroding and eroding flow rates) and compared with Newtonian flows under the same experimental conditions. For the clay-mineral suspensions, measurements of the kinematic viscosity v, Karman's constant k and the mean streamwise velocity of the logarithmic layer seemed to verify a Newtonian flow structure. Although the distributions of concentration showed no substantial increase towards the wall, it was found that beneath this Newtonian core there existed a viscous sublayer whose thickness was enhanced by a factor of 2–5. The friction velocity u* determined by the gradient method in the viscous sublayer was reduced by as much as 40 %. The mean flow structure exhibited an additional new layer in the region 10 < y+ < 30.The measurements indicate that turbulent-drag reduction occurs for the experimental clay-mineral suspension at non-eroding and also at eroding velocities. Agglomeration of suspended clay-mineral particles is suggested as possible explanation of this phenomenon.
109 citations
TL;DR: In this paper, the response curves of various plastic track detectors (CN, CA, PC, PET) were determined in the region of relatively low etching rate ratios, where the power index is about 3 within a limit ± 10% for pure materials.
109 citations
TL;DR: Various biopsies from different European malignant lymphomas, two biopsie from nasopha‐ryngeal carcinomas, and material from non‐neoplastic lymph nodes were assayed for the presence of Epstein‐Barr virus (EBV) DNA by nucleic acid hybridization.
Abstract: Various biopsies from different European malignant lymphomas, two biopsies from nasopha-ryngeal carcinomas, and material from non-neoplastic lymph nodes were assayed for the presence of Epstein-Barr virus (EBV) DNA by nucleic acid hybridization. Reassociation kinetics of in vitro-labelled EBV DNA were studied in the presence of tumor DNA. The lymphomas tested included among others follicular lymphomas, germinocytomas, immunoblastic lymphomas and lymphoplasmacytoid immunocytomas. Epstein-Barr viral DNA was demonstrated within the two nasopharyngeal carcinoma biopsies as expected. A histologically typical Burkitt lymphoma as well as an immunoblastic lymphadenopathy with excessive plasmacytosis also contained EBV-DNA. The Burkitt biopsy revealed about 15 EBV genome equivalents per cell. Antibodies against EBV-specific antigens were highly elevated in the serum of this patient. The material of the patient with immunoblastic lymphadenopathy contained 2-3 EBV genome equivalents per cell.
86 citations
TL;DR: Deep seismic sounding refraction studies made during the Narino Project, combined with other recent geophysical and geological data, show many features of the active boundary between the Nazca Plate and the South American Plate in Colombia as mentioned in this paper.
TL;DR: In this article, the authors used electropalatographic techniques to study the coarticulation between the intervocalic plosives of the VCV nonsense word and found that the relative frequency of right-to-left and left-toright co-articulations within and across both plosive types varied with the distance from one vowel to the other.
TL;DR: Viking 2 lander began imaging the surface of Mars at Utopia Planitia on 3 September 1976 as discussed by the authors, where the surface is a boulder-strewn reddish desert cut by troughs that probably form a polygonal network.
Abstract: Viking 2 lander began imaging the surface of Mars at Utopia Planitia on 3 September 1976. The surface is a boulder-strewn reddish desert cut by troughs that probably form a polygonal network. A plateau can be seen to the east of the spacecraft, which for the most probable lander location is approximately the direction of a tongue of ejecta from the crater Mie. Boulders at the lander 2 site are generally more vesicular than those near lander i. Fines at both lander sites appear to be very fine-grained and to be bound in a duricrust. The pinkish color of the sky, similar to that observed at the lander I site, indicates suspension of surface material. However, the atmospheric optical depth is less than that at the lander I site. After dissipation of a cloud of dust stirred during landing, no changes other than those stemming from sampling activities have been detected in the landscape. No signs of large organisms are apparent at either landing site.
TL;DR: Morphologic analysis indicates that the last dynamic event was one of general deflation for at least some drifts, and particle cohesion implies that there is a distinct small-particle upturn in the threshold velocity-particles size curve.
Abstract: Drifts of fine-grained sediment are present in the vicinity of the Viking 1 lander. Many drifts occur in the lees of large boulders. Morphologic analysis indicates that the last dynamic event was one of general deflation for at least some drifts. Particle cohesion implies that there is a distinct small-particle upturn in the threshold velocity-particle size curve; the apparent absence of the most easily moved particles (150 micrometers in diameter) may be due to their preferential transport to other regions or their preferential collisional destruction. A twilight rescan with lander cameras indicates a substantial amount of red dust with mean radius on the order of 1 micrometer in the atmosphere.
TL;DR: In this paper, the relative densities of Baltic Sea waters have been measured from 3.5 to 20‰ salinity and 0.36 to 20°C with a vibrating densimeter.
TL;DR: In this paper, Bowmans Deutung der Furkalaste als Uropoden is verstandlich, warum bei Vorhandensein von Furkalaasten der After immer terminal gelegen ist.
Abstract: Diese Arbeit nimmt zu Bowmans Ausfuhrungen (1971) uber das Telson der Crustacea Stellung. Es wird seiner Auffassung entgegengetreten, nach der die Definition des Telsons eine terminale Lage des Afters ausschliest. Entgegen Bowmans Darstellung ist eine solche Lage vielmehr fur das Telson der Thermosbaenacea, Spelaeogriphacea, Stygocarididae und Bathynellacea kennzeichnend. Auch fur einige Cumacea ist eine solche Lage angegeben worden. Die Lage der Afteroffnung wird als nebensachlich fur die Definition des Telsons angesehen, zumal Verlagerungen nicht nur von anderen Tiergruppen bekannt sind, sondern auch bei den Crustacea z.B. im Verlauf der Larvalentwicklung einiger Decapoda (z.B. Penaeidae) auftreten, bei denen sich durch Auswachsen des gegabelten Telsons die Offnung von terminal nach ventral verschiebt. Wichtiger fur die Definition des Telsons ist die Segmentsprossungszone. Unter Telson versteht man den Teil, der nach abgeschlossener Segmentierung hinter ihr ubrigbleibt, vorausgesetzt er bleibt nicht mit dem davorliegenden Segment zu einem Pleotelson vereinigt (z.B. Bathynellacea). Bowmans Deutung der Furkalaste als Uropoden ist nicht in allen Fallen aufrechtzuerhalten. Hier wird nur auf die Furkalaste der Nebaliacea und Bathynellacea eingegangen. Sie werden als beweglich gewordene Aste eines einstmals gegabelten Telsons gedeutet. Eine solche Deutung machte verstandlich, warum bei Vorhandensein von Furkalasten der After immer terminal gelegen ist. Abschliesend wird kurz auf die Funktion der Furka eingegangen.
TL;DR: In guinea-pig papillary muscles toxin II isolated from the sea anemone Anemonia sulcata (ATX), ATX enhanced the force of contraction without changing the time-to-peak tension and increased the relaxation time.
Abstract: 1.
In guinea-pig papillary muscles toxin II isolated from the sea anemone Anemonia sulcata (ATX) enhanced the force of contraction without changing the time-to-peak tension. ATX increased the relaxation time. The positive inotropic effect was accompanied by a prolongation in action potential duration. The action potential amplitude and the resting membrane potential remained essentially unchanged. The velocity of depolarization (dV/dtmax) decreased slightly. The effects were not modeified by pretreatment of the animals with reserpine.
2.
In preparations partially depolarized by elevated extracellular potassium (14.7 mM KCl) a concentration of 1×10−8 M ATX was ineffective with respect to increase in force of contraction or delay of repolarization. The effects of 1×10−8 M ATX could be reversed by 5×10−7 M tetrodotoxin.
3.
Our results suggest that ATX affects the action potential duration by delaying the inactivation of the fast sodium permeability change which initiates the action potential. It is not clear, however, in which manner this effect is related to the increase in force of contraction.
TL;DR: It can be demonstrated with the aid of Golgi-, Nissl-, and pigment preparations that the Betz cells represent a homogeneous class of giant cells within the human brain, which can readily be distinguished from other large pyramids by their densely aggregated lipofuscin deposits.
Abstract: It can be demonstrated with the aid of Golgi-, Nissl-, and pigment preparations that the Betz cells represent a homogeneous class of giant cells within the human brain, which can readily be distinguished from other large pyramids by their densely aggregated lipofuscin deposits. In addition to the primary motor field (4, Brodmann), there exists only a small area on the medial surface of the hemisphere in front of the central sulcus which also contains large Betz pyramids in layer Vb. This recently discovered gigantopyramidal field is almost totally buried in the depth of the cingulate sulcus (Braak, 1976b). Compared with the Betz cells of the primary motor field (4, Brodmann), those of the cingulate area display numerous primitive traits. A small number of short basal dendrites springs off from the cell body. The apical dendrite forks in a short distance from the perikaryon repeatedly but issues only few side branches. A spine-free proximal dendritic segment is poorly developed or lacking. Moreover, numerous spines are encountered along the surface of the soma. In view of their primitive features the large pyramids of the cingulate gigantopyramidal area are interpreted as the forerunners of the precentral Betz pyramids.
TL;DR: In this article, the stability field of the assemblage Mg-cordierite+K feldspar+quartz was shown to be limited on its low-temperature side by the breakdown of cordierite into muscovite, phlogopite and quartz, whereas the hightemperature limit was given by eutectic melting.
Abstract: Under hydrous conditions the stability field of the assemblage Mg-cordierite+K feldspar+quartz is limited on its low-temperature side by the breakdown of cordierite+K feldspar into muscovite, phlogopite and quartz, whereas the high-temperature limit is given by eutectic melting. The compatibility field of the assemblage ranges from 530° C to 745° C at 1 kbar \(P_{{\text{H}}_{\text{2}} {\text{O}}}\), from 635 to 725° C at 3 kbars \(P_{{\text{H}}_{\text{2}} {\text{O}}}\), from 695 to 725° C at 5 kbars \(P_{{\text{H}}_{\text{2}} {\text{O}}}\) and terminates at 5.5 kbars \(P_{{\text{H}}_{\text{2}} {\text{O}}}\). Most components not considered in the model system will tend to restrict this field even more. However, the condition \(P_{{\text{H}}_{\text{2}} {\text{O}}}\) < Ptotal will increase the range of stable coexistence drastically, making the assemblage common at elevated temperatures from contact metamorphic rocks up to intermediate pressure granulites of appropriate bulk composition.
TL;DR: The Hamilton-Depressions-Skala (HDSS) as mentioned in this paper is a formale formale analysis of depression, in which each symptom is associated with a specific aspect of depression.
Abstract: Im Rahmen von Psychopharmaka-Therapien wurde die Hamilton-Depressions-Skala bei 197 psychiatrischen Patienten je dreimal verwendet; dabei wurde eine erweiterte Version (24 Symptome) der Hamilton-Skala benutzt, die die ursprungliche miteinschliest. Verschiedene formale Analysen (Symptomhaufigkeiten, Einflus von Geschlecht, Itemanalysen, Konsistenz schatzung, Faktorenanalysen) lassen folgende Schlusfolgerungen zu: Bei der ursprunglichen Fassung ist die einfaktorielle Auswertung am adaquatesten; mehrere Faktoren sind nicht anzunehmen. Bei der erweiterten Version (vor allem in USA gebraucht) ist zwar die Einfaktorenlosung ebenso zu empfehlen, doch konnte man auch die Zweifaktorenlosung in Betracht ziehen, bei der zwischen gehemmt-depressiven und somatisch-depressiven Aspekten unterschieden wird. Der Gesamtwert bei der Hamilton-Skala ist von befriedigender Konsistenz (Reliabilitat) und kaum vom Geschlecht abhangig.
TL;DR: A hypothesis concerning the homing of lymphocytes to non-lymphoid tissues and the proliferation of extranodal lymphoid tumours is presented.
Abstract: Uptothepresentdaytherehasbeenno satisfactory explanation of why benign or malignant lymphomas can develop in the skin. Recently Goudie, MacFarlane & Lindsay (1974) presented an interesting hypothesis concerning the homing of lymphocytes to non-lymphoid tissues. The authors speculated that the proliferation of extranodal lymphoid tumours might be due to the possibility that neoplastic lymphocytes home on a special tissue by a process called ecotaxis (de Sousa, 1971). Ecotaxis means the accumulation of lymphocytes in territories which display their appropriate microenvironment.
TL;DR: It is concluded that type 1 neurones have vasomotor function and most type 2 neurones piloerection function.
Abstract: Postganglionic neurones to the tail's skin of the cat were investigated with regard to their spontaneous activity, response characteristics to somatic stimuli and asphyxia, the conduction velocity of their axons, and the conduction velocity of the preganglionic axons converging on them. The cats were anaesthetized with chloralose, immobilized, and arteficially ventilated. With this regimen the postganglionic neurones were divided into two types: 1. Type 1 neurones are spontaneously active and exhibit reflexes upon somatic stimulation. During asphyxia they are mostly first depressed and then excited for about 2–3 min. Their axons conduct with 0.57±0.13 m/s (mean ± SD). The preganglionic axons converging on them conduct with 5.4±1.6 m/s. 2. Type 2 neurones are not spontaneously active and exhibit with few exceptions no reflexes on somatic stimuli. During asphyxia they are activated after 3–4 min, concomitantly with piloerection, when the activity in type 1 neurones is already decreasing. Their axons conduct with 0.84±0.14 m/s, the preganglionic axons converging on them conduct with 9.9±2.9 m/s. 3. From these characteristics it is concluded that type 1 neurones have vasomotor function and most type 2 neurones pilomotor function.
01 Jan 1976-Journal of Comparative Physiology A-neuroethology Sensory Neural and Behavioral Physiology
TL;DR: It is suggested that the high potency of the toxins in the nanomolar range, their small size, the known composition and sequence of amino acids together with the specificity of action on the sodium channels, proved in different preparations, make these substances to important tools in the study of excitable membranes.
Abstract: 1.
The effects of three toxins (ATX I, II and III) from the sea anemoneAnemonia sulcata have been investigated on neuromuscular transmission and nerve action potentials in the crayfisch.
2.
In the neuromuscular preparations the toxins produce a gradual increase in the amplitude of the excitatory junction potentials until they reach the threshold for the generation of electrically excitable membrane responses. This is followed by repetitive activity of the motor axons, first on single stimuli, later occurring spontaneously.
3.
The effects of the three toxins differ only with regard to the effective concentrations: threshold concentrations amount to 5×10−9 M for ATX I and II, to 10−7 M for ATX III.
4.
The toxins show no postsynaptic effects on the muscle fibre membrane and on their electrical responses upon direct stimulation.
5.
All toxins prolong the action potentials of the giant axons in the abdominal nerve cord. The duration may reach more than one second. The rate of rise of the action potentials is not affected. In several cases, however, an increase of the amplitude of the action potential was observed.
6.
The effects of ATX I and II are irreversible in contrast to those of ATX III.
7.
It is suggested that the high potency of the toxins in the nanomolar range, their small size, the known composition and, in the case of ATX II, sequence of amino acids together with the specificity of action on the sodium channels, proved in different preparations, make these substances to important tools in the study of excitable membranes.
TL;DR: It is postulated that interstitial, water is flushed out of coarse-grained sediments by gravity displacement due to changes in the density of bottom water, in certain areas this mechanism of nutrient release from the sediments is presumably of great ecological importance, both for the phytoplankton and the benthos.
Abstract: Results of an enclosure experiment carried out in Kiel Bight are presented. A water column of about 30 m3, extending from the surface to the bottom over a 3 m2 patch of sediment (coarse sand), was isolated and observed over a period of 33 days. Considerable water exchange took place with the surroundings partly because of near-surface openings that appeared in the enclosure but mainly because of density changes due to salinity fluctuations in the surrounding water. This denser water entered the enclosure through the sediments, displacing the lighter water through the near-surface openings. Very high nutrient and low oxygen values were measured in the bottom water immediately following this higher-density water influx. The same effect was observed outside the enclosure, but this phenomenon was not marked here, probably due to greater turbulent mixing obscuring this effect. It is postulated that interstitial, water is flushed out of coarse-grained sediments by gravity displacement due to changes in the density of bottom water. In certain areas this mechanism of nutrient release from the sediments is presumably of great ecological importance, both for the phytoplankton and the benthos.
TL;DR: The threshold of the responses of these neurones to spinal cord heating was 40–42°C (on the dorsal spinal cord) and that the response increase was maximal at the highest temperatures tested (43–44°C).
Abstract: Single postganglionic neurones to hairy skin and hairless skin of the hindleg were investigated on spinal cord heating and spinal cord cooling in chloralose anesthetized cats. 1. Spontaneously active postganglionic neurones which were classified as vasoconstrictor neurones were depressed by spinal cord heating and excited by spinal cord cooling. The overall response to spinal cord cooling was smaller than that to spinal cord heating. 2. Postganglionic neurones to the hairless skin, which had most likely sudomotor function, responded initially to spinal cord heating with a few impulses or not at all. As judged by the skin potentials recorded from the hairless skin the sweat glands were also only weakly activated at the beginning of the heat stimuli. 3. Six silent postganglionic neurones, 3 each to the hairy skin and to the hairless skin, were excited during spinal cord heating. The response of these neurones consisted of a dynamic and a static component and started at the beginning of the heating stimuli with latencies of less than 10S. The neurones could not be excited by any other stimuli and were classified as cutaneous vasodilator neurones. 4. Quantitative analysis of 4 spontaneously active postganglionic (vasoconstrictor) neurones and 3 silent postganglionic (vasodilator) neurones revealed that the threshold of the responses of these neurones to spinal cord heating was 40-42 degrees C (on the dorsal spinal cord) and that the response increase was maximal at the highest temperatures tested (43-44 degrees C).?
TL;DR: In this article, the long chain compounds form bilayers between the niobate sheets and are arranged in gauche-block structures, which can change their dimensions by intercalation of small polar organic molecules.
TL;DR: In this paper, it is suggested that turbulent drag reduction occurs on a geophysical scale if the flows transport cohesive sediments and that drag reduction is caused by dynamic interaction between turbulent shear strain in the flow and deformation of aggregates.
TL;DR: In this paper, the mean-free path for inelastic electron-electron scattering decreases monotonically from values of the order of 1000 ε at the scattering threshold to values between 1 and 5 ε for electron energies 10 eV above threshold.
Abstract: The energy distributions of photoelectrons of solid Ar, Kr, and Xe films with thicknesses between 10 and 300 \AA{} have been measured in the photon energy range of 10 to 30 eV using the synchrotron radiation of Deutsches Elektronen Synchrotron (DESY). By varying the photon energy and the film thickness the dependence of the electron-electron scattering length on the electron kinetic energy has been determined. The mean-free path for inelastic electron-electron scattering decreases monotonically from values of the order of 1000 \AA{} at the scattering threshold to values between 1 and 5 \AA{} for electron energies 10 eV above threshold. The observed energy dependence can be understood by a simplified band structure and a scattering probability described by a product of the density of states. The threshold energy for electron-electron scattering lies between twice the energy of the $n=1$ excitons and the sum of band-gap and exciton energy.
TL;DR: Protein fractions preventing formation of ice crystals in water were isolated from the mussel Mytilus edulis using ion-exchange procedure and gel filtration and it is suggested that the occurrence of such antifreeze glycoproteins contributes essentially to the mechanism of freezing resistance in the mussels.
Abstract: Fractions of glycoproteins preventing formation of ice crystals in water were isolated from the mussel Mytilus edulis, using ion-exchange procedure and gel filtration. The protein fractions depress the freezing point of water more than would be expected from their concentrations, taking into account their molecular weights (>10 000 Daltons). It is suggested that the occurrence of such antifreeze glycoproteins contributes essentially to the mechanism of freezing resistance in the mussel.
TL;DR: In this article, a technique to record laser Raman-spectra of rotating solid samples at the temperature of liquid nitrogen in an evacuated cell is described, and the complete vibrational spectrum of the highly photosensitive K 3 [Fe(C 2 O 4 ) 3 ]·3H 2 O is obtained for the first time by the described low temperature technique.