Showing papers by "University of Bern published in 1982"
559 citations
TL;DR: In this article, the CO2 concentration of the air occluded in bubbles of ice samples from Camp Century and Byrd Station, using a new dry extraction technique, was analyzed with an IR-laser spectrometer (IRLS).
Abstract: Recent measurements1,2 on ice samples from Camp Century (Greenland, 77°10'N, 61°08'W), Byrd Station (Antarctica, 80°01'S, 110°31'W) and Dome C (74°40'S, 125°10'E) suggest that during the late part of the last glaciation the atmospheric CO2 concentration was significantly lower than during the Holocene. Further investigation of this natural increase of the atmospheric CO2 concentration in the past should aid our understanding of the climatic implications of the man-made CO2 increase since the beginning of industrialization3. Here we report new and precise measurements of the CO2 concentration of the air occluded in bubbles of ice samples from Camp Century and Byrd Station, using a new dry extraction technique. The extracted gases were analysed with an IR-laser spectrometer (IRLS). Samples from 22 different depths were analysed from each core. The samples are distributed over a depth interval corresponding approximately to the past 40,000 yr. In addition results for ice samples from selected depth horizons from a colder region (North Central, Greenland 74°37'N, 39°36'W) and from a warmer region (Dye-3, Greenland 65°11'N, 43°50'W) are given. Based on these results we estimate the trend of the atmospheric CO2 concentration during the past 40,000 yr.
459 citations
TL;DR: In this paper, an alternative approach is presented, formally relating unknown ages of samples to known ages of standards, either by direct comparison of standard and sample track densities, or by repeated calibration of a glass against age standards.
440 citations
TL;DR: Isoprenaline does not affect single channel conductance, but seems to lengthen the mean open time and to decrease intervals between bursts, which primarily determines the slow activation time course of averaged currents.
Abstract: The permeability of cell membranes to Ca2+ ions is of great importance for a variety of cellular functions such as secretion of neurotransmitters and hormones, or contractile activation of heart cells. In several cell types including cardiac muscle, Ca2+ channels are gated by membrane potential and regulated by neurotransmitters1–3. We have used the patch clamp technique4 in order to obtain information about the properties of single Ca channels in cultured heart cells. With Ba2+ carrying the inward current the single channel slope conductance is about 25 pS, and the probability of channel opening increases markedly with voltage. The channels become inactivated over a membrane potential range of about 60 mV. The mean channel open time is about 1 ms at 25 °C. However, a second much slower clustering behaviour primarily determines the slow activation time course of averaged currents. Isoprenaline does not affect single channel conductance, but seems to lengthen the mean open time and to decrease intervals between bursts.
306 citations
TL;DR: In this article, non-Abelian gauge fields on a four-dimensional hypercubic lattice with small action density were shown to carry an integer topological charge, which is invariant under continuous deformations of the field.
Abstract: Non-Abelian gauge fields on a four-dimensional hypercubic lattice with small action density [Tr{U(
$$\dot p$$
)} for SU(2) gauge fields] are shown to carry an integer topological chargeQ, which is invariant under continuous deformations of the field. A concrete expression forQ is given and it is verified thatQ reduces to the familiar Chern number in the classical continuum limit.
297 citations
TL;DR: This review may familiarize ‘newcomers’ with the field of glycoconjugate research with special emphasis on glycoprotein glycans and current knowledge on functional roles of glycans is presented.
Abstract: Since the pioneering work on structure and function of heteroglycans compiled in the classical books edited by A. Gottschalk in 19721, there have been several promising developments in glycoconjugate research, as reviewed in this article.
262 citations
TL;DR: In this article, the authors used multichannel microwave radiometer (SMMR) data to determine the extent, water equivalent, and onset of snow melt of the Nimbus-7 satellite.
Abstract: The Nimbus-7 satellite launched on October 24, 1978, carries a multifrequency, dual-polarized microwave imager. The instrument is designed to sense the ocean surface, the atmosphere, and land surfaces remotely. From previous ground-based and satellite-based microwave experiments, it is well known, that snow cover over land has a very distinct effect on the microwave signatures of the earth surface. It was the goal of this study to show that the three snow-cover parameters: extent, snow water equivalent, and onset of snow melt can be determined using scanning multichannel microwave radiometer (SMMR) data. Our analysis has shown, that the three snow parameters mentioned above are retrievable with sufficient accuracy to be of great value in climatology, meteorology, and hydrology. Snow extent is determined for dry snow cover with depth ?5 cm, snow water equivalent can be determined on a regional basis with ?2 g/cm2 rms accuracy, and the onset of snow melt is clearly visible by the detection of melt and refreeze cycles prior to snow runoff. The algorithms derived are simple enough to be incorporated in fully automated operational data analysis schemes.
235 citations
TL;DR: In this paper, the authors call for not merely economic and technical adjustments in policies, but for a fundamental political transformation in the conception of tourism and recreation, which could lead to the positive economic effects of tourism being outweighed by significant social and environmental disadvantages.
218 citations
TL;DR: The results point to the fact that further damage due to surgery and its risk to the remaining blood supply is less prominent in gentle exploration and minimal osteosynthesis than with a generous exposure needed for plate fixation, and minimal fixation thus should be preferred.
Abstract: This paper reports the results of 27 multi-fragmented fractures of the proximal humerus treated between 1972 and 1976. Only 3- and 4-part fractures as well as fracture dislocations were included. Internal fixation was performed in 17 cases with buttress plates and in 10 patients by minimal fixation with a tension band wire or simple lag screw. On an average of 3.5 years postoperatively out of 27 patients eight had excellent, eight a good, six a fair, and five a poor overall result. Radiologically six cases of avascu1ar necrosis of the humeral head (22.2%) were detectable in one 3-part, four 4-part and one fracture dislocation. Five times necrosis was observed after plate fixation (34%) once after wiring of the greater tuberosity. The incidence of unfavorable head necrosis is dependent on the primary fracture type. The results point to the fact that further damage due to surgery and its risk to the remaining blood supply is less prominent in gentle exploration and minimal osteosynthesis than with a generous exposure needed for plate fixation. Minimal fixation thus should be preferred.
190 citations
TL;DR: The data indicate that at the end of Cretaceous, when a high proportion of the ocean's planktic organisms were eliminated, an associated reduction in productivity led to a partial transfer of dissolved carbon dioxide from the oceans to the atmosphere, which resulted in a large increase of the atmospheric carbon dioxide during the next 50,000 years, which is believed to have caused a temperature rise revealed by the oxygen-isotope data.
Abstract: The latest Mesozoic and earliest Tertiary sediments at Deep Sea Drilling Project site 524 provide an amplified record of environmental and biostratographic changes at the end of Cretaceous. Closely spaced samples, representing time intervals as short as 102 or 103 years, were analyzed for their bulk carbonate and trace-metal compositions, and for oxygen and carbon isotopic compositions. The data indicate that at the end of Cretaceous, when a high proportion of the ocean9s planktic organisms were eliminated, an associated reduction in productivity led to a partial transfer of dissolved carbon dioxide from the oceans to the atmosphere. This resulted in a large increase of the atmospheric carbon dioxide during the next 50,000 years, which is believed to have caused a temperature rise revealed by the oxygen-isotope data. The lowermost Tertiary sediments at site 524 include fossils with Cretaceous affinities, which may include both reworked individuals and some forms that survived for a while after the catastrophe. Our data indicate that many of the Cretaceous pelagic organisms became extinct over a period of a few tens of thousands of years, and do not contradict the scenario of cometary impact as a cause of mass mortality in the oceans, as suggested by an iridium anomaly at the Cretaceous-Tertiary boundary.
189 citations
TL;DR: The study has shown that gingivitis can be controlled successfully on a longitudinal basis using .1 % or .2 % mouthrinses of CH as an adjunct to daily toothbrushing.
Abstract: The study tested the effects of supervised chlorhexidine digluconate (CH) mouthrinses on plaque and gingivitis in school children. 158 children (aged 10–12 years) participated in the study. They were divided into four groups matched according to age, sex. DMFS, and GI. Following a sealing and prophylaxis procedure. Group A was assigned to daily mouthrinses 6 times per week using a .2 % solution of CH. Group B used the same solution only twice per week, and Group C was assigned to daily rinsing using a .1 % solution of CH. Group D served as control and rinsed daily with a placebo solution. All the rinsings were supervised and timed for 30 seconds. No attempt was made to influence the oral hygiene habits of the children. Prior to the initial prophylaxis and after 6 months of supervised rinsing, plaque was scored using the Plaque Index (PII), and gingivitis was assessed using the Gingival Index (GI). Calculus was scored according to the Calculus Surface Index (CSI), and stain was also graded. DMFS indices were assessed using clinical and radiographic examinations. At the end of the study plaque was significantly reduced in all CH groups when compared with the controls, and calculus increased significantly in all CH groups. In Group A the GI dropped from .88 to .15 and in Group C from .80 to .24. In Group B the GI dropped from .79 to .38. In the control group a slight reduction from GI = .93 to GI = .75 was noted. The study has shown that gingivitis can be controlled successfully on a longitudinal basis using .1 % or .2 % mouthrinses of CH as an adjunct to daily toothbrushing.
TL;DR: Seeded beam expansions of high-temperature sodium vapour in helium, neon, argon, krypton and nitrogen carrier gases are examined in this paper, where photoionization coupled with mass spectroscopic detection is used to determine beam constituents.
TL;DR: The distribution of total tranverse energy ΣET over the pseudorapidity interval −1 < η < 1 and an azimuthal range Δφ=300° has been measured in the UA2 experiment at the CERN pp collider (s = 540 GeV) using a highly segmented total absorption caloriter as discussed by the authors.
TL;DR: In this article, neutral carrier-based liquid membrane micro-electrodes were constructed which are suitable for continuous measurements of [Mg(2+)](i) in cardiac and skeletal muscle preparations.
Abstract: 1. Neutral carrier-based liquid membrane micro-electrodes were constructed which are suitable for continuous measurements of [Mg(2+)](i) in cardiac and skeletal muscle preparations.2. The electrodes show a Nernstian behaviour in pure MgCl(2) solutions. In the presence of a constant ionic background chosen to simulate the cytoplasmic composition, the calibration function flattens progressively with lower [Mg(2+)], due to the interference of K(+) and Na(+). The response to changes in [Mg(2+)] is less than 0.5 sec.3. In quiescent preparations at room temperature (23 degrees C), the following basal [Mg(2+)](i) were determined: 3.5 mM (sheep Purkinje fibres), 3.1 mM (sheep ventricular muscle), 3.0 mM (ferret ventricular muscle) and 3.3 mM (frog skeletal muscle).4. In cardiac tissue, electrical stimulation does not measurably affect the basal [Mg(2+)](i).5. In the presence of 0.5 mM-Mg(2+) (o), the calculated Mg(2+) equilibrium potentials, E(Mg), are in the range of -23 to -25 mV, suggesting that Mg(2+) is not passively distributed across the sarcolemma in striated muscle.6. Further studies were performed on sheep Purkinje fibres to investigate the effect of various experimental interventions on [Mg(2+)](i).7. Elevating [Mg(2+)](o) from 0.5 to 10 mM resulted in a reversible increase of [Mg(2+)](i). The initial rate of increase corresponds to a Mg(2+) influx of 0.42 p-mole/cm(2).sec, or a magnesium permeability, P(Mg), of 1.6 x 10(-8)cm/sec.8. Increasing P(CO) (2) from nominally 0 to 100 mmHg (Tris-buffered vs. bicarbonate-buffered Tyrode solution) produced a reversible decrease in [Mg(2+)](i) by roughly 0.45 mM, probably due to Mg(2+) binding the newly formed intracellular HCO(3) (-).9. The effect of metabolic poisoning on [Mg(2+)](i) was assessed by exposure to cyanide, iodoacetic acid and 2-4-dinitrophenol. No significant increase in [Mg(2+)](i) indicative of a liberation of Mg(2+) from ATP was observed.
TL;DR: Comparison of structural and enzymic properties of aldose reductase with those of other carbonyl reductases suggests a relationship between aldOSE reduct enzyme and aldehyde reductased (EC 1.1.2).
Abstract: Aldose reductase (EC 1.1.1.21) from human brain has been purified to apparent homogeneity. The enzyme catalyzes the NADPH-dependent reduction of several physiological and xenobiotic aldehydes. Isocorticosteroids, e.g. isocortisol and isocorticosterone, are the best substrates (Km less than 1 micron), followed by aromatic and arylalkyladehydes, including biogenic aldehydes (Km = 3 - 15 microM). The activity towards aldoses is highest with glyceraldehyde (Km = 25 microM) and decreases with increasing number of carbon atoms of the sugar. Flavonoids, e.g. quercetin and rutin, inhibit aldose reductase (IC50 = 2 - 5 microM). Sulfate ions, on the other hand, stimulate the enzyme activity. Thiol-modifying reagents, e.g. 4-hydroxymercuribenzoate and iodoacetate, cause a time-dependent inactivation. Aldose reductase consists of a single polypeptide chain with a molecular weight of 38 000 and an isoelectric point of 5.9. In the presence of thiol reagents the isoelectric point is shifted to 5.1. Antibodies against aldose reductase do not cross-react with other carbonyl reductases, Nevertheless, the comparison of structural and enzymic properties of aldose reductase with those of other carbonyl reductases suggests a relationship between aldose reductase and aldehyde reductase (EC 1.1.1.2).
TL;DR: In this paper, it was shown that the odd solutions of (*) are additive and the even ones are quadratic (cf., e.g., ([8], [12]), and the results obtained included the classical case of the inner product orthogonality as well as the three following generalizations thereof: (i) Birkhoff-James orthogonomies on a normed space, (ii) orthogonsality induced by a non-isotropic sesquilinear functional, (iii) semi-inner product orthomorphisms on a
Abstract: The conditional Cauchy functional equationF: (X, +, ⊥) → (Y, +), F(x + y) = F(x) + F(y) x, y ∈ X, x ⊥ y, has first been studied under regularity (mainly continuity and boundedness) conditions and by referring to the inner product and the Birkhoff—James orthogonalities (A. Pinsker 1938, K. Sundaresan 1972, S. Gudder and D. Strawther 1975). The latter authors proposed an axiomatic framework for the space (X, +, ⊥), and it then became possible to modify their axioms so that it could be proved without any regularity condition that the odd solutions of (*) are additive and the even ones are quadratic (cf., e.g., ([8], [12]). The results obtained included the classical case of the inner product orthogonality as well as the three following generalizations thereof: (i) Birkhoff—James orthogonality on a normed space, (ii) orthogonality induced by a non-isotropic sesquilinear functional, (iii) semi-inner product orthogonality.
TL;DR: In this paper, the absence of C 20 -hydrocarbon precursors of crocetin supports a degradation pathway for the biosynthesis of crocodetin in Crocus sativus.
TL;DR: The most precise current value of the hyperfine Zeeman transitions in the ground state of muonium is obtained from the value of $\frac{{m}_{\ensuremath{\mu}}}{{m}_e}}$ is obtained.
Abstract: New higher precision measurements of the hyperfine Zeeman transitions in the ground state of muonium have been performed with use of the high-stopping-density surface ${\ensuremath{\mu}}^{+}$ beam at the Clinton P. Anderson Meson Physics Facility. The results are $\ensuremath{\Delta}\ensuremath{
u}=4463\ensuremath{-}302.88(16)$ kHz (0.036 ppm) and $\frac{{\ensuremath{\mu}}_{\ensuremath{\mu}}}{{\ensuremath{\mu}}_{p}}=3.1833461(11)$ (0.36 ppm). The current theoretical value of $\ensuremath{\Delta}\ensuremath{
u}$ agrees well with experiment within the 0.77-ppm error of $\ensuremath{\Delta}{\ensuremath{
u}}_{\mathrm{theor}}$, which is due principally to inaccuracy in evaluation of the nonrecoil radiative correction term. The most precise current value of $\frac{{m}_{\ensuremath{\mu}}}{{m}_{e}}$ is obtained from our value of $\frac{{\ensuremath{\mu}}_{\ensuremath{\mu}}}{{\ensuremath{\mu}}_{p}}$.
TL;DR: In this article, a Monte Carlo measurement of the topological susceptibility χt = 〈Q2〉/volume (Q: topological charge) in the lattice O(3) σ model revealed that χ t does not scale like a (mass)2 for large β = inverse bare coupling constant.
TL;DR: A short description is given of the laboratory experience gained in oral immunization of foxes against rabies, and its application in a limited field trial in Switzerland with an attempt to control two outbreaks of fox rabies.
Abstract: A short description is given of the laboratory experience gained in oral immunization of foxes against rabies, and its application in a limited field trial in Switzerland with an attempt to control two outbreaks of fox rabies.
01 Jan 1982
TL;DR: In this paper, the authors explain why kartieren wir die Schweizer Flora: "Weil es hochste Zeit ist zu inventarisieren in einer Zeit, wo der Mensch Umwelt und Natur bedenkenlos in Anspruch nimmt, wo wir doch so vieles noch nicht wissen, unsere Landschaften sehr ungleich kennen, wo unsere bisherige Information zu uberaltern droht, wo neue systemat
Abstract: Warum kartieren wir die Schweizer Flora? Weil es hochste Zeit ist zu inventarisieren in einer Zeit, wo der Mensch Umwelt und Natur bedenkenlos in Anspruch nimmt, wo wir doch so vieles noch nicht wissen, unsere Landschaften sehr ungleich kennen, wo unsere bisherige Information zu uberaltern droht, wo neue systematische Erkenntnisse neue Nachforschungen verlangen.
TL;DR: In this paper, the method of dimensional regularization for quantum field theories with large (i.e., not infinitesimal) classical background fields is introduced and discussed in detail for the case of quantum fields with large background fields.
TL;DR: In this article, passive electrical properties of sheep cardiac Purkinje fibres were assessed by performing linear cable analysis and it was concluded that the changes in ri are directly caused by protons and not indirectly via secondary changes of the [Ca2+]i.
Abstract: 1. Passive electrical properties of sheep cardiac Purkinje fibres were assessed by performing linear cable analysis. In a separate set of experiments pHi was monitored using recessed-tip pH-sensitive micro-electrodes.
2. In Tris-buffered Tyrode solution (nominally CO2-free), the pHi was 7·27, in bicarbonate-buffered solution equilibrated with 6% CO2, the mean pHi was 7·02.
3. Application of 15 mM-NH4Cl produced a rapid intracellular alkalinization (0·19 pH units), followed by a slower acidification. Removal of NH4Cl gave rise to a slow and transient intracellular acidification (0·5 pH units).
4. The biphasic and transient shift in pHi, induced by the NH4Cl treatment, was accompanied by a change of the inside longitudinal resistance per unit fibre length, ri, displaying a similar time course. The increase in pHi produced a maximum decrease in ri of 16·4%, while the decrease in pHi yielded a maximum increase in ri of 30·4%.
5. Changing from bicarbonate-buffered Tyrode solution equilibrated with 6% CO2 to Tris-buffered Tyrode solution led to an increase in pHi (0·26 pH units). A subsequent change to bicarbonate-buffered Tyrode solution equilibrated with 15% CO2 produced a decrease in pHi (0·48 pH units). Both changes were sustained.
6. This CO2 protocol gave rise to corresponding changes in ri; the intracellular alkalosis was associated with a decrease in ri (21·2%), and the intracellular acidosis was accompanied by an increase in ri (30%).
7. Based on recent findings showing an interaction between pHi and pCai (Hess & Weingart, 1980), it is concluded that the changes in ri are directly caused by protons and not indirectly via secondary changes of the [Ca2+]i.
8. The pHi-dependent changes in ri are likely to reflect alterations of the nexal resistance, rn, because the cytoplasmic resistance, rc, has the inverse sensitivity to pHi.
9. Unlike pCai, pHi would seem to be able to modify the cell-to-cell coupling by increasing or decreasing ri over a rather narrow range, without ever producing electrical uncoupling.
10. Because of basic differences in the action of calcium and protons on the cell-to-cell coupling (magnitude of the effect, operative concentration range), it is tempting to conclude that there is more than one kind of binding site which controls the nexal conductance.
TL;DR: In this paper, a universal expansion for the masses of the low-lying stable particles in pure Yang-Mills gauge theories and non-linear ω-models is proposed.
TL;DR: In this article, the authors determined the temporal dependence of 36Cl fallout by measuring the depth profile in an ice core from Dye 3 Greenland (65° 11′ N, 43° 50′ W) using tandem accelerator mass spectrometry.
Abstract: Nuclear weapons tests at oceanic sites during the 1950s produced a large amount of 36Cl (t1/2 = 3.0 × 105 yr) through neutron capture of 35Cl in seawater. Part of this anthropogenic 36Cl was injected into the stratosphere from where it was redistributed throughout the Earth. This pulse of 36Cl was first detected in rainfall by Schaeffer et al.1. The global deposition rates are several orders of magnitude larger than the natural pre-and post-bomb 36Cl production rate that reflects cosmic-ray spallation of atmospheric 40Ar. Because 36Cl is not a fission product, the anthropogenic 36Cl is produced mainly in marine tests carried out on small islands and barges where a large amount of seawater chlorine is present to serve as a target. This target element requirement leads to a temporal dependence different from the other bomb produced isotopes2–4. We have determined the temporal dependence of 36Cl fallout by measuring the depth profile of 36Cl in an ice core from Dye 3 Greenland (65° 11′ N, 43° 50′ W) using tandem accelerator mass spectrometry5. We show here that the results agree well with a calculation of the 36Cl produced and injected into the stratosphere by the tests.
TL;DR: In this paper, several mechanisms of element and isotope fractionation are discussed in relation to observed abundances and their variations and data on composition in the solar wind are summarized and compared with best estimates of abundances in the outer convective zone of the Sun.
Abstract: Data on composition in the solar wind are summarized and compared with best estimates of abundances in the outer convective zone of the Sun. Several mechanisms of element and isotope fractionation are discussed in relation to observed abundances and their variations.
TL;DR: Treatment for ARDS includes elimination of the cause of ARDS, early institution of mechanical ventilation with PEEP, prompt recognition and treatment of superimposed infections, and careful management of additional organ failures.
TL;DR: In this paper, the authors show that the 30% change in 15N14N in solar-wind-bearing lunar soils and breccias probably does not reflect changes in this ratio at the solar surface.
TL;DR: The quality of tissue preservation in lungs fixed by vascular perfusion has been reevaluated and results include large increases of perfusion pressure and lung weight that reflect intracellular, interstitial, and intra-alveolar edema.
Abstract: The quality of tissue preservation in lungs fixed by vascular perfusion has been reevaluated. Excised rabbit lungs inflated to 60% of total lung capacity were perfused (zone III conditions) with different but widely used fixatives. The effects of the perfusates on pertinent physiological variables have been assessed by a continuous monitoring, the effects on the pulmonary microstructure by qualitative and morphometric analysis of electron micrographs. Important results include the following. 1) Perfusions with isotonic glutaraldehyde at flow rates within the physiological range produce large increases of perfusion pressure and lung weight that reflect intracellular, interstitial, and intra-alveolar edema. 2) No edema occurs if glutaraldehyde is added to isotonic buffer solutions (total osmolarity 510 mosM). 3) Glutaraldehyde as sole perfusate does not fully eliminate the retractive force of lung tissue. Upon release of transpulmonary pressure the lungs retract by an indeterminable amount. 4) Satisfactory results can be obtained by sequential perfusion with osmium tetroxide and uranyl acetate or glutaraldehyde (510 mosM) followed by osmium tetroxide and uranyl acetate. The latter combination yields optimal preparations to study the alveolar and capillary architecture but causes a hyperosmotic volume loss of lung cells (cell shrinkage).
TL;DR: The data suggest that the R. sphaeroides oxidase does not function as a proton pump and is cross-reactive with antibodies directed against the oxidases from Paracoccus denitrificans and Saccharomyces cerevisiae.
Abstract: When grown aerobically in the dark, Rhodopseudomonas sphaeroides develops a respiratory chain similar to that in mitochondria and the photosynthetic apparatus is suppressed. The aa3-type cytochrome c oxidase from Rps. sphaeroides has been purified in Triton X-100 by affinity chromatography with Sepharose 4B coupled to yeast cytochrome c. The oxidase contains 14 nmol heme a/mg protein and is composed of three polypeptide subunits with relative molecular masses of 45000, 37000 and 35000. The enzyme is highly active in the presence of detergents, with a maximal velocity of 300s−1/mol oxidase using either yeast or horse-heart cytochrome c.
The Rps. sphaeroides oxidase is cross-reactive with antibodies directed against the oxidases from Paracoccus denitrificans and Saccharomyces cerevisiae. A particularly close relationship is indicated in the case of P. denitrificans. The Rps. sphaeroides oxidase has been incorporated into phospholipid vesicles. The resulting oxidase in these vesicles demonstrates high enzymatic activity and a respiratory control ratio of 5. Using these vesicles, no evidence for proton extrusion accompanying cytochrome c oxidation was observed. The data suggest that the Rps. sphaeroides oxidase does not function as a proton pump.