Showing papers by "University of Bern published in 1978"
TL;DR: A short survey of application areas and selection criteria for the different remote-sensing methods is presented in this article, where experimental results of microwave probing are presented with examples from agriculture, meteorology, and hydrology.
Abstract: A short survey of application areas and selection criteria for the different remote-sensing methods is presented. Microwave sensing is still regarded as one of the more progressive methods and its problem of angular resolution and the principle of synthetic-aperture radar are discussed. Experimental results of microwave probing are presented with examples from agriculture, meteorology, and hydrology.
327 citations
TL;DR: It is demonstrated that the relative underweight (weight loss corrected for height) is most pronounced in children with predominantly pulmonary symptoms, and closely correlates inversely with survival.
Abstract: On the basis of observations in 117 children with cystic fibrosis, seen from January 1956 to June 1976, it is demonstrated that the relative underweight (weight loss corrected for height) is most pronounced in children with predominantly pulmonary sypmtoms. The degree of underweight closely correlates inversely with survival. Because of its prognostic value, it is recommended that this clinical parameter be included in the checkups which are periodically carried out on children suffering from cystic fibrosis.
304 citations
TL;DR: It has been found that the main inhibitors for calcium phosphate and calcium oxalate precipitation are citrate, pyrophosphate, and perhaps magnesium; among the synthetic inhibitors, the diphosphonates are the most powerful for both processes.
301 citations
TL;DR: In this paper, the relativistic Hamiltonian quantum theories of finitely many degrees of freedom were investigated and a class of solutions of the angular condition was provided by a particular type of local manifestly covariant wave equations.
267 citations
TL;DR: Results from different models for the natural carbon dioxide cycle are compared and special emphasis is given to the type of ocean modeling, behavior of the biosphere, and value of the oceanic buffer factor against carbon dixoide uptake.
Abstract: Results from different models for the natural carbon dioxide cycle are compared. Special emphasis is given to the type of ocean modeling (diffusive deepsea or two-box ocean), behavior of the biosphere, and value of the oceanic buffer factor against carbon dixoide uptake. According to the most probable models, the fraction of the cumulative production remaining airborne will be between 46 and 80 percent 100 years from now for any realistic assumptions concerning future carbon dioxide production. For a prescribed maximum increase of 50 percent above the preindustrial carbon dioxide level, the production could grow by about 50 percent until the beginning of the next century, but should then decrease rapidly.
208 citations
TL;DR: It is demonstrated that without profound sodium depletion, age may be more important than sodium excretion as a frame of reference for judging both renin and norepinephrine measurements; both factors should be considered for interpretation of PA.
182 citations
TL;DR: The GEOS-1 ion composition experiment has surveyed plasma composition at all local times in the L range 3~8 and the energy per charge range from thermal to 16 keV/e.
Abstract: After one year of operation the GEOS-1 Ion Composition Experiment has surveyed plasma composition at all local times in the L range 3~8 and the energy per charge range from thermal to 16 keV/e. From measurements made in the keV range during eleven magnetic storms we find that the percentage of heavy (M/Q > 1) ions present in the outer magnetosphere increases by a factor of 3 to 10 during disturbances. We conclude that two independent sources (solar wind, characterized by 4He2+, and ionosphere, characterized by O+) give on the average comparable contributions to injected populations, although in a single event one or the other source may dominate. However, in magnetically quiet periods protons are the dominant species with a few percent of heavy ions. With the help of special satellite manoeuvres magnetic field aligned fluxes of ≈0.05–3 keV/e H+, He+, O+ with traces of O2+ have been observed which may be related to ion beams found previously at lower altitudes in the auroral zone. At still lower energies (~1 eV/e) the thermal plasma population is found to be made up of six ion species, three of which, D+, He2+ and O2+, were unknown in the magnetosphere prior to the GEOS-1 measurements. We present here a study of the evolution of doubly charged ions and their parent populations over four consecutive days. Various production mechanisms for doubly charged ions are discussed. We argue that ionization of singly charged ions by UV and energetic electrons and protons is the dominant process for plasmasphere production. Furthermore, the observed high concentrations of O2+ at high altitudes are a result of production in the upper ionosphere and plasmasphere combined with upward transport by thermal diffusion.
174 citations
TL;DR: In this article, the chemistry of 33 basaltic rocks dredged from the West Mariana basin and from the Mariana trench during the R/V “Dmitry Mendeleev” 1976 cruise in the western Pacific is described.
160 citations
TL;DR: In this article, an independent model is developed for estimating the size-shape bivariate histogram of a finite population of variable spheroids (either prolate, or oblate) uniformly and isotropically scattered within an arbitrary specimen.
Abstract: SUMMARY
Mathematical relationships linking the size-shape probability density function (pdf) of an infinite population of variable spheroids uniformly and isotropically scattered in space on the one hand, with the size-shape pdf of the ellipses produced by a plane of section on the other, have recently been published (Cruz Orive, 1976). In the present paper, an independent model is developed for estimating the size-shape bivariate histogram of a finite population of variable spheroids (either prolate, or oblate) uniformly and isotropically scattered within an arbitrary specimen, from the corresponding histogram of the elliptical profiles produced by an arbitrary section (or sections) through the whole specimen. The approach is stochastic, allowing the estimation of the variance-covariance matrix of the ‘unfolded’ size-shape spheroid frequencies.
The numerical reliability of the methods is checked by means of an example, whereas a practical guide illustrates and summarizes the unfolding procedure.
Natural ways of estimating spheroid properties, alternative to those found in Cruz Orive (1976), are presented.
142 citations
TL;DR: In this paper, the power dependence of the ion current of Na as a function of the wavelength of the tunable cw dye laser (excitation) and of the Ionizing Ar+- or Kr+-laser, conditions under which true spectra are obtained have been clarified.
Abstract: The investigation of electronic and structural parameters of metal molecules as a function of size may be decisive for understanding and control of heterogeneous catalysis with finely divided metals. Metal-atom clusters can be prepared by several methods, most of which yield a molecular mixture only. Expansion of an atomic vapour into vacuum through a supersonic nozzle creates a complex cluster-spectrum which has been investigated by photoionization using a mass-spectrometer as selective detector. Broad band single photoionization (PI.) yields the abundances and ionization thresholds for Nax(x⩽16), Kx(x⩽12) and NaxKy(x+y⩽6). Rough indications about other deactivation channels of excited alkali-molecules are obtained from an analysis of the photoionization efficiency (PIE.) curves. Two-photon PIE. curves with narrow-band (laser) light sources give an accurate photoionization threshold value and detailed information on ionization processes. Two-photon ionization spectra via a real intermediate state reached by laser excitation are equivalent to normal absorption spectra, if the exciteation step is controlled by the true transition probabilities. By investigation of the power dependence of the ion current of Na as a function of the wavelength of the tunable cw dye laser (excitation) and of the ionizing Ar+- or Kr+-laser, conditions under which true spectra are obtained have been clarified, in good agreement with a photon-kinetic model of the processes involved. Vibronic and rovibronic spectra of several transitions in Na2 and K2 have been measured. Similarly a spectrum of Na3 has been determined mass-selectively. The scope of the new method for an absorption spectroscopy in molecular beams is discussed.
132 citations
TL;DR: The fringes are dynamically translated over the object, and the phase of the signal picked up at a selected point on the surface is used to determine the depth or the depth error of the profile at this point.
Abstract: A method of profile control or measurement using projected fringes is presented. The fringes are dynamically translated over the object, and the phase of the signal picked up at a selected point on the surface is used to determine the depth or the depth error of the profile at this point. The method has the advantage of being contact-free, fast, accurate, and easily automated.
TL;DR: In this paper, a pair of high-sensitivity (1 cm2 · sr · eV) high-resolution (M/?M? 10 at focus) ion mass spectrometers were used to study the ion composition of the ring current, the plasma sheet, the plasmasphere, the magnetosheath, and the solar wind in order to establish the origin of the plasmas in the various regimes of the magnetosphere and to identify mass and charge dependent acceleration, transport, and loss processes.
Abstract: The plasma composition experiment on ISEE-A consists of a pair of high-sensitivity (~1 cm2 · sr · eV) high-resolution (M/?M ? 10 at focus) energetic ion mass spectrometers. They cover the entire mass range from 1 AMU to > 150 AMU in 64 channels at each of 32 energy channels covering the energy per charge range from 0 to approximately 17 keV/e. The objectives of the experiment are to study the ion composition of the ring current, the plasma sheet, the plasmasphere, the magnetosheath, and the solar wind in order to establish the origin of the plasmas in the various regimes of the magnetosphere and to identify mass and charge dependent acceleration, transport, and loss processes.
TL;DR: Red blood cells from adult humans are able to keep the Ca concentration in the cytosol several orders of magnitude below that of blood plasma, indicating that the Ca2+ concentration may be as low as M or less in the normal state of the cell (Cao2+ = M).
Abstract: Red blood cells from adult humans are able t o keep the Ca concentration in the cytosol several orders of magnitude below that i n blood plasma.'*' Information from functional behavior and comparison of inward and outward movement through the m e m b ~ a n e ~ . ~ indicate that the Ca2+ concentration may be as low as lo-' M or less in the normal state of the cell (Cao2+ = M). As we shall see, maintenance of a Ca2+ gradient of 10,000 across the membrane is possible because of low passive permeability and the operation of an outwardly directed Ca pump mechanism in the plasma membrane. Red cells lend themselves particularly well to the study of Ca movements across the plasma membrane for several reasons. ( I ) They are anatomically simple. The absence of internal compartments surrounded by membranes reduces the formidable complications encountered in more complex cells. ( 2 ) Difficulties arising in solid tissues due to the extracellular space are avoided. (3) Binding to intracellular compounds exists but does not create insurmountable problems because it opposes rather than concurs with active transport, which is in the outward direction. (4) Several techniques are available to introduce Ca into the red cell without doing too much harm to the plasma membrane. These are: reversible hemolysis,5 temporary exposure to a n ionophore such as A 23187,3 exposure to high concentration of lyotropic anions such as salicylate?' exposure to parachloromercuribenzene sulfonate (PCMBS).7 and metabolic starvation in Ca-rich solution^.^ (5) Passive Ca movements across the plasma membrane are sufficiently slow to allow thorough washing in cold Ca-free media without disturbing the Ca content of the cells.
TL;DR: The estrogen-induced synthesis of vitellogenin in the frog Xenopus and the chicken is an attractive system for investigating the molecular events leading to the activation of a specific gene and the events occurring at the level of the protein and mRNA in the cytoplasm are discussed.
TL;DR: Along the southern margin of the Damara orogen age and degree of metamorphism were determined by means of K/Ar dating and illite crystallinity as mentioned in this paper, and the age of the Nama beds corresponds to the higher part of the anchi-zone and lower epi-zone.
Abstract: Along the southern margin of the Damara orogen age and degree of metamorphism were determined by means of K/Ar dating and illite crystallinity. The investigations include the following units:
The metamorphism of the Naukluft nappes as well as the underlying Nama beds corresponds to the higher part of the anchi-zone and lower epi-zone. Between the Naukluft nappes and the folded Nama rocks adjoining the southeastern front of the nappes there is an obvious step from higher down to lower metamorphism. Further to the southeast the metamorphism in the Nama beds decreases continuously down to diagenesis. K/Ar age determinations were carried out on the three units mentioned above and also on the basement underlying the Nama sequence. Muscovites of this basement gave an age of about 1160 m. y. Determinations on white micas of the southern Damara belt, the Naukluft Mountains and the northern Nama basin define two isochrons with ages of 495 and 530 m. y The age of 530 m. y. represents the peak of metamorphism and the age of syncrystalline deformation. The age of 495 m. y. can be interpreted as a cooling age of the higher metamorphic rocks or as a dating of rejuvenation caused by a second post-crystalline deformation in parts of the Naukluft and Damara rocks. This age of 495 m. y. was also found in the mylonite of the main thrust plane of the Naukluft nappes and it represents the time of emplacement of the Naukluft nappes.
TL;DR: In this paper, two-electrode thin layer experiments have been carried out in the system Ag(hkl)/Pb 2+, ClO 4 − in order to determine independently the charge and Pb 2 + coverage fluxes of the lead underpotential adsorption.
TL;DR: In this paper, the authors analyzed 2-4 mm sieve fraction of three Apollo 16 soils collected in the vicinity of North Ray Crater (63503,17 at Station 13, 67603,1 and 67703,14 at Station 11).
TL;DR: Characteristic changes in haemolymph juvenile hormone (JH) titre, corpus allatum (c.a.) volume, and c.a. in vitro activity occur during the oocyte maturation phase of the ovoviviparous cockroach Nauphoeta cinerea, indicating a positive correlation between these parameters and suggesting that JH is possibly synthesized in pulses and not continuously.
TL;DR: The proteolipid, which specifically and covalently binds dicyclohexylcarbodiimide, has an apparent molecular weight of 8,000 in dodecylsulfate electrophoresis and the minimum molecular weight calculated from amino acid analysis data is 7,700.
Abstract: Characterization of a butanol-solubilized protein isolated from chloroplast membranes is reported. The proteolipid, which specifically and covalently binds dicyclohexylcarbodiimide, has an apparent molecular weight of 8000 in dodecylsulfate electrophoresis. The minimum molecular weight calculated from amino acid analysis data is 7700. N-Formyl-methionine was determined to be the N-terminal amino acid. Glycine, alanine and leucine were present in elevated amounts, resulting in a polarity of 29%. Cysteine and histidine were lacking. In high-voltage electrophoresis the peptide appeared as a single homogenous spot which migrated, at pH 6.5, with the relative mobility of glycine. At concentrations where dicyclohexylcarbodiimide inhibited ATPase activity maximally (20 nmol per mg membrane protein), 0.17 nmol dicyclohexylcarbodiimide was covalently bound per nmol isolated proteolipid, indicating that one out of six molecules of proteolipid was labeled.
TL;DR: The uptake of inorganic pyrophosphate from blood to bone was investigated in the rat in vivo and it appears that the technetium complexes behave in a similar fashion to free PPi or diphosphonate.
Abstract: 1. The uptake of inorganic pyrophosphate (PPi) from blood to bone was investigated in the rat in vivo. 2. PPi is taken up by the bone, where it appears both as PPi and as inorganic orthophosphate (Pi). The latter is due at least partly to local hydrolysis. 3. The fraction of injected PPi taken up by bone, measured as total PPi, was in the same range as that of technetium-tin-PPi, diphosphonates, technetium-tin-ethane-1-hydroxy-1,1-diphosphonate and Pi, but lower than that of calcium. 4. The plasma half-life of PPi is in the same order of magnitude as that of technetium-tin-PPi, diphosphonates, technetium-tin-ethane-1-hydroxy-1,1-diphosphonate, Pi and calcium. 5. PPi, diphosphonates and their technetium complexes are only partly ultrafiltrable in plasma. 6. It appears that the technetium complexes behave in a similar fashion to free PPi or diphosphonate.
TL;DR: In this article, the adsorption behavior of Tl+ on Ag(100) and Ag(111) in 0.5 M NaClO4 and Na2SO4 has been studied by voltammetric methods including flow-through thin layer voltammetry (FTTL) and single electrode thin layer voltage measurement (STL).
TL;DR: It is suggested that the primary defect in the pathogenesis of "cold" follicles in old mice is the gradual failure of endocytosis to respond to normal TSH stimulation, which would have impaired iodination while being metabolically as active as hot ones.
Abstract: Autoradiographs of thyroid glands of aging mice demonstrate the gradual appearance of “cold” follicles which fail to iodinate the intraluminar iodoproteins even after intense exogeneous or endogeneous TSH stimulation “Cold” follicles first appear at the age of 5 months They may account for 80% of all thyroid follicles in 13-month-old mice Morphologically, the “Cold” follicles are characterized by a larger than normal colloid volume and a comparatively flat epithelium for any given follicle size Old thyroids are twice as large as young ones They contain twice as much normally iodinated thyroglobulin/mg wet weight The total number of cells per gland remains constant throughout the life time This is probably also true for the total number of follicles The iodide pump, as judged by the tissue to serum ratio, remains normal and TSH-responsive Yet, it is not established whether this is due to a higher activity of the pump in normal follicles or to preservation of inorganic iodide transport in “Cold” fo
TL;DR: Quantitative separation of eight multiple molecular forms of acetylcholinesterase isolated from human erythrocyte membranes was accomplished by sucrose density gradient centrifugation in a zonal rotor indicating that hydrophobic interactions are important in the formation of these oligomeric forms.
Abstract: Quantitative separation of eight multiple molecular forms of acetylcholinesterase isolated from human erythrocyte membranes was accomplished by sucrose density gradient centrifugation in a zonal rotor. Hydrodynamic properties of the four most abundant oligomers were investigated by analytical ultracentrifugation. The S20, w values obtained for these components ranged from 12.5 S to 19.0 S with corresponding molecular weights between 500 000 and 1 131 000. These oligomers are built up of 6-14 subunits. Analysis of each isolated homogenous form after storage for 6 months at 4 degrees C revealed interconversion into the original eight components. Upon addition of Triton X-100 the oligomers disaggregate to yield a single 7-S form, which reaggregates upon removal of the detergent. Such reaggregation can be prevented by chaotropic ions indicating that hydrophobic interactions are important in the formation of these oligomeric forms.
TL;DR: In this paper, the authors measured the gas content and composition of Camp Century ice core from Greenland and compared the results with measurements of 18O/16O ratio, electrical conductivity, pH values and crystal size.
Abstract: VARIATIONS of physical and chemical properties of ice cores have been observed by many authors1–3. These variations could be attributed to temperature effects, different origins of moisture and changes in concentrations and isotopic composition of atmospheric constituents. We report here data from parameters measured in a section of the Camp Century ice core from Greenland. Gas content and composition were measured systematically in a continuous set of samples covering ∼2 yr of precipitation. The data are compared with measurements of 18O/16O ratio, electrical conductivity, pH values and crystal size. The aim of the investigation was to determine which parameters show random and which seasonal variations. Special consideration is given to the CO2 content, which is higher in the gas extracted from natural ice than in the atmosphere4 and shows short-term variations which cannot be explained by variations of the atmospheric CO2 content alone. These probably reflect variations in the meteorological conditions at the time of precipitation. Meterological conditions may influence other parameters of the ice in a similar way. If such correlations could be found, one might be able to correct the observed CO2 variations for the meterological effect and sort out the effect related to changes in the atmospheric CO2 content. Measurements of the CO2 content of ice cores of different age could then be used to reconstruct the history of the atmospheric CO2 content from present to 100,000 yr BP.
TL;DR: This simple and sensitive method is especially suitable for determining substrate specificities for physiological amines as well as for inhibitor studies with pargyline or the monoamine oxidase A- and B-specific inhibitors clorgyline and deprenyl.
TL;DR: The activity of adenosine 5'-phosphosulfate sulfotransferase is restored within 24 hours after transfer to a culture medium without cysteine, which suggests that the cyst(e)ine pool is involved in the in vivo regulation of the enzyme.
Abstract: When 0.5 mm cysteine is added to cultures of Lemna minor L. growing with sulfate as the sole sulfur source, there is a rapid 80% loss of extractable adenosine 5′-phosphosulfate sulfotransferase. This loss is accompanied by an inhibition of sulfate uptake; however, lack of sulfate is not responsible for the decreasing adenosine 5′-phosphosulfate sulfotransferase activity. Cultivation with cysteine causes an increase in the cyst(e)ine pool of L. minor. This fact taken together with the observed inactivation of adenosine 5′-phosphosulfate sulfotransferase in crude extracts by cysteine suggests that the cysteine pool is involved in the in vivo regulation of the enzyme. The activity of adenosine 5′-phosphosulfate sulfotransferase is restored within 24 hours after transfer to a culture medium without cysteine. This restoration is partially blocked by 6-methyl purine and actinomycin D and completely by cycloheximide. Cycloheximide added to cultures of L. minor L. causes a loss of extractable APSTase comparable to the one obtained with cysteine. This loss may be in part due to cysteine, since cycloheximide causes a pronounced increase in the cysteine pool of L. minor.
TL;DR: Embryos of the ovoviviparous cockroach Nauphoeta cinerea are shown to contain ecdysteroids and juvenile hormone dependent on their stage of development and the site of synthesis is not yet known.
TL;DR: In this article, an attempt has been made to combine data from five instruments on GEOS-1 in order to determine the characteristics of the ambient cold plasma, assess the effects of spacecraft sheaths on the different techniques and establish cross calibration criteria.
Abstract: An attempt has been made to combine data from five instruments on GEOS-1 in order to determine the characteristics of the ambient cold plasma, assess the effects of spacecraft sheaths on the different techniques and establish cross calibration criteria. In addition to measuring plasma density and temperature it is necessary to consider the influence of satellite potential and motion, ionic composition, ion drifts (electric fields), electrons emitted from spacecraft surfaces and any consequent departures from isotropy or Maxwellian distribution.
TL;DR: In this article, the identification of nucleation in the process of underpotential deposition is studied using a general model including homogeneous adsorption as well as 2D-phase formation.
TL;DR: Findings point towards important differences between fetal and adult bile metabolism and may reflect maturation of hepatic bile acid biosynthesis near term.
Abstract: Individual bile acids were determined in twenty-nine amniotic fluid specimens obtained from twenty-six women between the 32nd and 41st week of gestation. Total bile acid concentration ranged from 0.4 to 4.8 mumol/l with a mean of 1.57 mumol/l. Besides the two major bile acids of man, cholic acid and chenodeoxycholic acid, 3beta-hydroxy-5-cholenoic acid was found in all, lithocholic acid in ten and deoxycholic acid in nine of the twenty-nine amniotic fluid samples. 3beta-Hydroxy-5-cholenoic acid averaged 39.8% of total bile acids during 32-37 weeks of gestation and 20.2% at term (P less than 0.01). These findings point towards important differences between fetal and adult bile metabolism and may reflect maturation of hepatic bile acid biosynthesis near term.