Sulfur isotope values in a forested catchment over four years: Evidence for oxidation and reduction processes

A small catchment on the Swedish West Coast has been studied over four years to determine S dynamics by using S isotope ratios. A Norway spruce dominated forest covers the catchment, and small peat areas occur in the lower parts of the catchment. The runoff values varied both during the year, and from year to year. Over the period from February 1990 to December 1993, the values ranged from — 1%. to +11%. Over the same period, the throughfall values ranged from +1%. to +15%. There was no correlation (r ²= 0.01; Pr(F)=0.57) between values in throughfall and runoff. Since the only input of S to the catchment is atmospheric deposition, the long-term runoff S mass flux is controlled by the deposition. Therefore, processes in the catchment are responsible for the variation in the runoff values. During periods with enriched runoff, bacterial dissimilatory SO ₄ ^2– reduction occurs in the catchment. After very dry periods, oxidation of this reduced S, which is³²S-enriched, can be traced in runoff. Previous studies of the catchment have not been able to distinguish between: 1) oxidation of reduced S and dry deposition, and 2) reduction and adsorption. From the current study, it can be concluded that adsorption and dry deposition cannot cause the observed variation in runoff .     

A directed alteration of ribonuclease specificity. Hydrolysis of polyribonucleotides containing modified cytosine bases

The action of ribonucleases on poly and oligoribonucleotides containing cytosine bases modified by methoxyamine and bisulphite was examined. Resistance of phosphodiester bonds in (Cp) _n Xp (where n 1 and X stands for A, G or U) to T₂ RNase hydrolysis was observed if substrates were modified chemically. The phenomenon formed the basis for isolation of (Cp) _n Xp blocks as an additional tool in sequence investigations. After modification of cytosine pancreatic RNase was unable to hydrolyse (Cp) _n Up blocks. Therefore the specificity of pyrimidyl RNase may be narrowed to uridyl RNase.Abbreviations cytidine modified with methoxyamine and bisulphite (5, 6-dihydro-6-sulpho-N⁴-methoxycytidine) - cytidine modified with methoxyamine (N⁴-methoxycytidine)     

A mathematical model of biological evolution

In order to understand generally how the biological evolution rate depends on relevant parameters such as mutation rate, intensity of selection pressure and its persistence time, the following mathematical model is proposed: dN _n (t)/dt=(m _n (t-)N _n (t)+N _n-1(t) (n=0,1,2,3...), where N _n (t) and m _n (t) are respectively the number and Malthusian parameter of replicons with step number n in a population at time t and is the mutation rate, assumed to be a positive constant. The step number of each replicon is defined as either equal to or larger by one than that of its parent, the latter case occurring when and only when mutation has taken place. The average evolution rate defined by is rigorously obtained for the case (i) m _n (t)=m _n is independent of t (constant fitness model), where m _n is essentially periodic with respect to n, and for the case (ii) (periodic fitness model), together with the long time average m of the average Malthusian parameter . The biological meaning of the results is discussed, comparing them with the features of actual molecular evolution and with some results of computer simulation of the model for finite populations.An early version of this study was read at the International Symposium on Mathematical Topics in Biological held in kyoto, Japan, on September 11–12, 1978, and was published in its Procedings.     

Control of acid-base status in active and dormant land snails,Otala lactea (Pulmonata,Helicidae)

Summary Control of extracellular acid-base status was examined during activity and dormancy inOtala lactea (Pulmonata, Helicidae). Active snails showed little variation in hemolymph pH and at constant temperature. With increase of temperature, hemolymph increased from about 6 Torr at 5°C to 13 Torr at 24°C and pH decreased by about 0.017 pH units/°C, a pattern consistent with alphastat regulation of pH via ventilatory control of .During dormancy, mean hemolymph increased to about 50 Torr. Venous pH declined by about 0.4 units due to hypercapnia and fluctuated more widely than in active snails due to variability of . Hemolymph pH declined further in prolonged dormancy due to progressive metabolic acidosis; after one year of dormancy the mean hemolymph pH was about 0.8 units lower than that of active snails at similar temperature.Active snails exposed experimentally to high showed a large increase in hemolymph [HCO ₃ ^– ]. However, [HCO ₃ ^– ] declined by up to 50% during dormancy, despite the naturally occurring hypercapnia. Hemolymph osmolality and the concentrations of solutes other than [HCO ₃ ^– ] increased with increasing duration of dormancy. Concentrations of magnesium and calcium increased about 2.5 times more rapidly than those of sodium and chloride, indicating that acidosis is partially offset by the dissolution of carbonates from the shell or tissues.     

A comparative study of the mechanism of Na+ and Cl? excretion by the gill ofMugil capito andFundulus heteroclitus: Effects of Stress

Summary In seawater (SW)-adaptedMugil andFundulus, gill effluxes of Na⁺ and of Cl^– and the simultaneously recorded transgill potential (P.D.) differ according to whether they are measured in stressed or rested animals.In rested animals of the two species, transfer to Ringer's solution considerably reduces the P.D. but not . InFundulus, is also decreased. Transfer of the two species from SW to fresh water (FW) reduces and by 75 to 85% and leads to a large inversion of P.D. When K⁺ is added to FW, a gill depolarization occurs, as well as a large increase of and .These results suggest that: 1) the P.D. originates primarily from the diffusion of cations, the gill permeability to Na⁺ ( ) being greater than that to Cl^– ( ), 2) a Cl^–/Cl^– exchange independent of P.D. is associated with the Cl^– pump; 3) Cl^– pump activity is linked to Na⁺/K⁺ exchange which in turn is associated to a Na⁺/Na⁺ exchange diffusion mechanism.In stressed individuals of the two species, the P.D. in SW, as well as the P.D. changes observed during transfer experiments, are considerably reduced. The decrease of and observed after transfer from SW to FW are also minimised. Changes are smaller inFundulus. The decrease of P.D. characterizing stressed animals may be at least in part due to a 3 to 4 fold increase of which becomes equal to in both species.As a result of stress, the K⁺-activated Na⁺ and Cl^– excretion mechanisms are totally inhibited inFundulus and partially so inMugil.Stress response seems more intense inFundulus and recovery from stress faster inMugil.     

Über Romanowsky-Farbstoffe und den Romanowsky-Giemsa-Effekt

Zusammenfassung Es wurden analysenreine Proben der Romanowsky-Farbstoffe Eosin Y, Erythrosin B und Tetrachlorfluoreszein hergestellt.Im DC der Farbstoffproben konnten keine Verunreinigungen nachgewiesen werden. Die Absorptionsspektren der Farbstoffdianionen in wäßriger alkalischer Lösung und der Farbstoffsäuren in 95%igem Ethanol wurden bei sehr kleinen Farbstoffkonzentrationen gemessen und der molare Extinktionskoeffizient der längstwelligen Absorptionsbande der monomeren Farbstoffspezies bestimmt (Tabelle 1). Die Extinktionskoeffizienten können zur Standardisierung von Farbstoffproben verwendet werden. Die Absorptionsspektren von Eosin Y hängen in wäßriger Lösung von der Farbstoffkonzentration ab. Aus der Konzentrationsabhängigkeit wurden mit einem neuen, sehr empfindlichen Verfahren zwei Assoziationsgleichgewichte ermittelt. Bereits in sehr verdünnter Lösung bilden sich Dimere, bei erhöhter Konzentration Tetramere, Die Dissoziationskonstante der DimerenD in MonomereM beträgt bei pH=12, 293K:K ₂₁=2,9 × 10^–5 M; der TetramerenQ in DimereD:K ₄₂=2,4 × 10^–3 M. Aus den gemessenen Spektren von Eosinlösungen verschiedener Konzentration, pH=12, und den GleichgewichtskonstantenK ₂₁,K ₄₂ haben wir die Spektren der reinen Monomeren, Dimeren und Tetrameren bestimmt.M hat eine langwellige Absorptionsbande: , _M =1,03 x 10₅ M_-1 cm_-1;D eine Bande: , _D =1,74 x 10₅ M_-1 cm_-1;Q zwei Banden: , , _Q1=1,65 x 10⁵, _Q2=1,96 x 10⁵ M^-1 cm^-1. Das Absorptionsspektrum der Dimeren wird quantenmechanisch interpretiert.

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Romanowsky dyes and Romanowsky-Giemsa effect. 2. Eosin Y, Erythrosin B, tetrachlorofluorescein, Spectroscopic characterization of pure dyes, association of Eosin Y

Summary Analytically pure smaples of the Romanowsky dyes eosin y, erythrosin b and tetrachlorofluorescein are prepared. DC of the dye samples shows no contaminations. We measured the absorption spectra of the dye dianions in alkaline aqueous solution and of the dye acids in 95% ethanol at very low dye concentrations. The molar extinction coefficients of the long wavelength absorption of the monomeric dye species are determined (Table 1). The extinction coefficients may be used for standardisation of dye samples. The absorption spectra of eosin y in aqueous solution are dependend on concentration. Using a new very sensitive method it was possible to identify two association equilibria from the concentration dependency of the spectra. Dimers are formed even in very dilute solutions, at higher concentrations tetramers. The dissociation constant of the dimersD in monomersM at 293 K, pH=12, isK ₂₁=2,9×10^–5 M; of the tetramersQ in dimersDK ₄₂=2,4×10^–3 M. From the experimental spectra of eosin solutions at various concentrations, pH=12, and the equilibrium constantsK ₂₁,K ₄₂ the absorption spectra of the pure monomers, dimers and tetramers are calculated. M has one long wavelength absorption band, , _M =1,03 x 10₅ M_-1 cm_-1;D also one absorption band, , _D =1,74 x 10₅ M_-1 cm_-1;Q two absorption bands, , , _Q1=1,65 x 10⁵, _Q2=1,96 x 10⁵ M^-1 cm^-1. The absorption spectrum of the dimers is discussed by quantum mechanics.

     

Contribution to the genetics of serum β-lipoproteins in man

Summary The genetic behaviour of a human serum -lipoprotein factor, called Ag(a₁), was studied by agar micro-diffusion technique, utilizing an antibody detected in the serum from a transfused thalassemia patient. It behaves as an inherited, dominant, autosomal character, with complete penetrance at birth. It is controlled by a gene and is closely linked to the Ag ^x and Ag ^y genes.The existence of a gene Ag ^b , allelic to , is postulated but the Ag(b) antigen has not so far been detected by specific antisera.The frequency of the gene in a Milan population was found to be 0,43, and in a Berne population was 0,46. The frequencies of the four possible gene combinations in the sample group from Milan were: Ag ^yb =0,53; =0,22; =0,21; Ag ^xb =0,04.The observed frequencies of the factor Ag(a₁) were 0,676 and 0,713, respectively among the Milan and Berne populations.     

Effects of wind on thermoregulation and energy balance in deer mice (Peromyscus maniculatus)

Summary The effects of various convective and temperature regimes on heat production, evaporative heat loss, and thermal resistance were studied in deer mice,Peromyscus maniculatus. Heat production (measured as oxygen consumption) increased with increasing wind speed (V) and decreasing ambient temperature (T _a), except atT _a=35°C which was thermoneutral for allV from 0.05 through 3.75 m/s. Evaporative water loss ( ) increased with increasingT _a, but wind had little effect on except at highT _a. In the absence of forced convection, the animals' total resistance to heat transfer (r _t) was high and stable atT _a below thermoneutrality. However, at highV ther _t increased steadily with decreasingT _a. Although deer mice rarely experience high wind speeds in natural microhabitats, the convective regime is nevertheless important in determining rates of heat loss, and must be considered in studies of ecological energetics.Symbols and Abbreviations A animal surface area - HP _n net metabolic heat production - EHL evaporative heat loss - MHP metabolic heat production - r _t total resistance to heat transfer - r _ext external resistance component of r_t - RQ respiratory quotient - pc _p volumetric specific heat of air - T _a ambient temperature - t _b body temperature - t _e operative, or equivalent blackbody temperature of the environment - T _sk skin temperature - T _es standard operative temperature - V wind speed - oxygen consumption - carbon dioxide production - evaporative water loss     

Age-Related Changes in Oxygen Consumption in the Edible Mussel <Emphasis Type="Italic">Mytilus edulis</Emphasis> from the White Sea

We determined the rate of oxygen consumption in the White Sea edible mussel Mytilus edulis of different ages. The mass-specific rate of oxygen consumption proved to decrease with mussel age according to the equation: = 40.1/(1 – e ^–0.194t ), where is mass-specific rate of oxygen consumption and t is age. Allometric coefficients of the oxygen consumption rate–soft tissue weight relationship were also determined.     

Serological identification of sperm antigens specified by lethalt-alleles in the mouse

Cytotoxic antisera were prepared by immunizing wild-type recipient mice with sperm from donors carrying different recessive lethal alleles at theT locus (T/t ⁰,T/t ^{w 1} ,T/t ^{w 5} , andT/t ^{w 32} ). After removal of sperm autoantibody by absorption with sperm of recipient type, each antiserum reacted only with sperm from males whose genotype contained at least one of the immunizing alleles. Cytotoxicity was high against sperm populations in which both immunizing alleles were represented and was lower when only one was present. Thus, each allele at theT locus which has so far been tested serologically is recognizable as a discrete antigen on the surface of sperm.This paper is dedicated to Professor Hans Grüneberg, F.R.S. on the occasion of his retirement from the chair of Animal Genetics at University College London, in appreciation of the fact that it was he who first suggested that surface properties played an important role in the origin of abnormalities associated with mutants at theT-locus.     

Contribution to the genetics of serum β-lipoprotein in man

Summary The study of some families of the double black cross type confirmed complete linkage of theAg ^x/y , andAg ^c/g loci.

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Zusammenfassung An Hand einer Untersuchung einiger Familien vom double back cross-Typ konnte das komplette linkage der Gen-LociAg ^x/y , undAg ^c/g bestätigt werden.

     

Proportionality of ELF electric field-induced growth inhibition to induced membrane potential inZea mays andVicia faba roots

Summary The postulate that 60-Hz electric field-induced bioeffect severity is proportional to induced transmembrane potential [ ] magnitude was tested and supported using a plant root model cell system. Statistically significant correlations were obtained upon regression of the relative rates of exposedVicia faba andZea mays root segment growth on the average (calculated) arising in those segments under specified 60 Hz field exposure conditions. The associated with the apparent threshold for growth inhibition was similar inZea andVicia roots (2.5 vs 2.4 mV, respectively). At greater than this threshold,Zea root growth declined by about 9% per mV, andVicia root growth by about 19% per mV induced potential.Abbreviations EF electric field - RGR relative growth rate - RSGR relative segmental growth rate - induced membrane potential - segmental-average induced membrane potential - VC _d region of root tip in which a complete, nascent vascular cylinder is first distinguishable in histological sections     

Effects of temperature and altitude on ventilation and gas exchange in chukars (Alectoris chukar)

Summary The effects of ambient temperature (T _a) on ventilation and gas exchange in chukar partridges (Alectoris chukar) were determined after acclimation to low and high altitute (LA and HA; 340 and 3,800 m, respectively).At both LA and HA, oxygen consumption ( ) increased with decreasingT _a atT _a from 20 to –20°C. AtT _a of 35 to 40°C, increased above thermoneutral values at HA but remained constant and minimal at LA. Water loss rates increased rapidly atT _a>30°C at both altitudes as birds began to pant. Ventilation rates (f) during panting were 5-to 23-fold greater than the minimalf at thermoneutralT _a.Increased atT _a below thermoneutrality was supported by increased minute volume (V i) at both altitudes. The change inV i was primarily a function of changing tidal volume (V t), althoughf increased slightly asT _a declined. Oxygen extraction ( ) remained fairly constant atT _a below 20°C at both altitudes. BothV t and were considerably lower when birds were panting than at lowerT _a.Chukars showed few obvious ventilatory adaptations to HA. The 35% change in between 340 and 3,800 m was accommodated by a corresponding change inV i (btps), most of which was accomplished by increasedf at HA, along with a slight increase in .Abbreviations and symbols HA high altitude - LA low altitude - rate of evaporative water loss - oxygen extraction efficiency - f respiratory frequency - V t tidal volume - V i minute volume - BMR basal metabolic rate - MHP metabolic heat production     

Oxygen controlled batch cultivations of Schizophyllum commune for enhanced production of branched β-1,3-glucans

Oxygen and shear stress are the key factors for enhanced glucan production with Schizophyllum commune. During batch cultivation control of or (specific oxygen uptake rate) was achieved by variation of the impeller speed. Biomass was modelled by using the carbon and oxygen balance derived from exhaust data. At mycel growth a of 0.042 h^–1 presents just the border before oxygen limitation arises and is simultaneously the optimum operation condition for maximum glucan formation. Related to an overall cultivation time of 72 h a maximum of both productivity (4.3 kg m^–3 d^–1) and yield (13 kg m^–3) were obtained.List of Symbols C kg m^–3 concentration - k _L a h ^–1 volume related oxygen transfer coefficient - K _s mol m^–3 substrate saturation constant - N rpm impeller speed - % oxygen partial pressure of the liquid phase - kg m^–3h^–1 oxygen uptake rate - h^–1 specific oxygen uptake rate, kg O₂ (kg biomass h)^–1 - t h time - yield coefficient (biomass formed/oxygen consumed) Greek Symbols h^–1 specific growth rate Indices O ₂ oxygen - X biomass - L liquid phase - * gas/liquid interface - S substrate (glucose) Dedicated to the 65th birthday of Professor Fritz Wagner.This work was kindly supported in parts by B. Braun Biotech International. The authors are grateful to Prof. Dr. Fritz Wagner for scientific support and appreciate the technical assistance of Detlev Rasch     

Effect of oxygen on the growth (yield) of Chlorella vulgaris

The growth yield of Chlorella vulgaris, Y _kJ defined as g cells harvested per kJ of light energy absorbed by the cells, was assessed in a turbidostat culture by varying CO₂ and O₂ partial pressures ( and ). The value of Y _kJ ranged from 3.1×10^-3 to 5.0×10^-3 g cells/kJ under light-limited conditions [ = 1.02.4%, = 065%; total pressure of gas (composed of CO₂, O₂ and N₂)=1 atm]. In the light-limited environment, the algal specific growth rate deteriorated appreciably with the increase of . The deterioration accounts for the above range of Y _kJ observed. The growth inhibition due to oxygen that was defined by subtracting from 1.0 the ratio of at given values of to that at = 0% extended from 0.07–0.30 (7–30%). However, glycolate could not be detected in the turbidostat culture. Isotopic experiments on the specific rate of ¹⁴CO₂ uptake also revealed that the inhibition due to oxygen was from 22–38% when was varied from 0 to nearly 100%. These effects of oxygen were discussed, referring to the activity of ribulose-1,5-bisphosphate carboxylase that is inhibited competitively by oxygen.Non-Standard Abbreviations INH isonicotinic acid hydrazide - PPO 2,5-diphenyloxazole - DCMU 3-(-3,4-dichlorophenyl)-1,1-dimetylurea - CA carbonic anhydrase - RuP₂ ribulose-1,5-bisphosphate     

Energy requirements of Adélie penguin (Pygoscelis adeliae) chicks

Summary The energy requirements of Adélie penguin (Pygoscelis adeliae) chicks were analysed with respect to body mass (W, 0.145–3.35 kg, n=36) and various forms of activity (lying, standing, minor activity, locomotion, walking on a treadmill). Direct respirometry was used to measure O₂ consumption ( ) and CO₂ production. Heart rate (HR, bpm) was recorded from the ECG obtained by both externally attached electrodes and implantable HR-transmitters. The parameters measured were not affected by hand-rearing of the chicks or by implanting transmitters. HR measured in the laboratory and in the field were comparable. Oxygen uptake ranged from in lying chicks to at maximal activity, RQ=0.76. Metabolic rate in small wild chicks (0.14–0.38 kg) was not affected by time of day, nor was their feeding frequency in the colony (Dec 20–21). Regressions of HR on were highly significant (p< 0.0001) in transmitter implanted chicks (n=4), and two relationships are proposed for the pooled data, one for minor activities ( ), and one for walking ( ). Oxygen consumption, mass of the chick (2–3 kg), and duration of walking (T, s) were related as , whereas mass-specific O₂ consumption was related to walking speed (S, m·s^-1) as .Abbreviations bpm beats per minute - D distance walked (m) - ECG electrocardiogram - HR heart rate (bpm) - ns number of steps - RQ respiratory quotient - S walking speed (m·s^-1) - T time walked (s) - W body mass (kg)     

Sodium chloride absorption across the ileal epithelium of the lizardGallotia galloti

Summary Ion transport processes in the ileum of the lizard,Gallotia (=Lacerta) galloti was examined in vitro by measuring Na²² and Cl³⁶ fluxes across short-circuited preparations.In Ringer-bicarbonate solution there was both a net sodium flux ( ) and a net chloride flux ( ) from mucosa to serosa. The inequality between and short-circuit current (I _sc) suggests that part of the net sodium transport is the result of an electrically neutral transport mechanism or that another electrogenic mechanism opposite in sign is contributing to the short-circuit current.In the absence of sodium, the short-circuit current and net chloride flux were abolished. In the absence of chloride, the net sodium was reduced but not abolished and the short-circuit current was unchanged.From an analysis of the effects of the inhibitors furosemide, amiloride, disulfonic stilbene (DIDS) and acetazolamide, a plausible model was developed to explain the characteristics of these transports. It is proposed that the entry of sodium into the cell across the luminal membrane occurs by two pathways. Part occurs by the antiport Na⁺H⁺ and part by an electrogenic pathway. The entry of chloride is by the antiport Cl^–HCO ₃ ^– .Symbols and abbreviations DIDS 4,4 diisothiocyanatostilbene-2,2-disulfonic acid - G _t tissue conductance - I _sc short circuit current - m mucosal - PD potential difference - s serosal     

Suitability of the shaking flask for oxygen supply to microbiological cultures

Due of its simplicity the shaking flask is used in serial studies, e.g. in the screening for secondary metabolites or in the optimization of fermentation processes. Experimental investigations in these small bioreactors are often the first step in developing a large-scale fermentation process.Movement of the flask should produce sufficient mixing, supply of oxygen, and removal of carbon dioxide. In the case of fluids with low or moderate viscosity, gas transport is the most important aspect. This publication summarizes data necessary to calculate the gas transport. These data are derived from the consideration of the gas diffusions through the cotton plug as well as from the substance transport between the gas and liquid phases. As a result suitable fermentation conditions can be selected. Finally, the performance limits of the shaking flask are illustrated using the example of the oxygen supply in a Streptomyces tendae fermentation.List of Symbols A _s Cross section of plug - A Surface area of liquid in flask - a A/V _F specific phase interface area - c Concentration - c ^* Saturation concentration - c Plug diffusion term - D Widest diameter of flask - Diffusion coefficients in multicomponent gas mix tures - Diffusion coefficients in binary gas mixtures - Diffusion coefficient of oxygen in the liquid - d Diameter of neck of flask - e Eccentricity - G Volume-based mass flow - G _m Maximum volume-based mass flow - g Acceleration due to gravity - h Height coordinate - ¯H Mean height of plug - Hy p _i/c ^*, Henry constant - K Consistency index - k D _xy/D _xz, Ratio of diffusion coefficients in binary gas mixtures - k _M Monod constant - k _L a Mass transport coefficient: gas/liquid - M Molecular weight - m Flow exponent - n Speed of shaking - p Pressure - p _i Partial pressure of gas component i - q Area-based flow of volume - R , respiration ratio - Sc , Schmidt number - T Absolute temperature - V Flask volume - V _F Volume of liquid in flask - w Velocity of the Stefan flow - x, y, z Ratios of the partial pressures of the gases O₂, CO₂, N₂ - Rate of shear - Dynamic viscosity of the liquid - Kinematic viscosity of the liquid - Density of the liquid - _x, Density of O₂ gas - Surface tension Indices 0 State in gas volume of shaking flask - 1 State in outside air - G Gas volume - x, y, z O₂, CO₂, N₂     

Determination of heteronuclear three-bond J-coupling constants in peptides by a simple heteronuclear relayed E.COSY experiment

Summary A simple heteronuclear relayed E.COSY pulse sequence with a minimum number of pulses is proposed for the quantitative determination of heteronuclear three-bond J-coupling constants in uniformly ¹³C-enriched polypeptide samples. Numerous heteronuclear three-bond coupling constants, including , , , and , can be determined for each residue from a single heteronuclear relayed E.COSY spectrum. Couplings relevant for stereospecific assignments as well as for the determination of dihedral angles in the amino acid backbone and in side chains are obtained. The method is demonstrated on the uniformly ¹³C-enriched decapeptide antamanide (-Val¹-Pro²-Pro³-Ala⁴-Phe⁵-Phe⁶-Pro⁷-Pro⁸-Phe⁹-Phe¹⁰-).