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Aeration in higher plants
(1979)
Sesame, Sesamum indicum L. (syn.S. orientale L.) belongs to family Pedaliaceae and is perhaps the oldest oilseed crop known to man. It is an annual, maturing in 70 to 140 days, but usually in 105 days or less, and contains 45-60% oil in its small, flat, oblong seeds which, may be white, brown or black.
3,17 β-Hydroxysteroid dehydrogenase has been enriched and purified from cytosol of Streptomyces hydrogenans. After ammonium sulfate precipitation and filtration on Sephadex G-100 the enzyme was finally purified by preparative gel electrophoresis and DEAE-Sephadex A-50 chromatography. Polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate gave a single band of mobility corresponding to molecular weight of 70 200 ± 2 500. 3 β-. 17 β- as well as 20 β-hydroxy steroids were dehydrogenated by the enzyme in the presence of NAD+. The dehydrogenation proceeded faster than the reduction of the corresponding ketosteroids in the presence of NADH. The enzyme does not accent NADP+ or NADPH as co-substrates. The apparent Km values were calculated to be 11 μᴍ for 5 α-dihydrotestosterone, 20 μᴍ for testosterone ana 68 μᴍ for epiandrosterone in the NAD+-driven reaction, 1.8 x 10-4 m for NADH+ and 1.9 x 10-4 ᴍ for NADH. The catalytic activity was influenced by the ratio of NAD+/ATP. The inhibition by ATP appears to be of a competitive type with respect to NAD+ (Ki 1.15 x 10-3 ᴍ).
After sucrose gradient centrifugation in a preparative ultracentrifuge the enzyme sediments with 4.1 ± 0.1 S as estimated in comparison to other proteins of known sedimentation coefficient. The isoelectric point was determined to be 3.9 with the LKB preparative isoelectric focusing column (pH 2-11) and 4.1 with the analytical flat bed polyacrylamide isofocusing (pH 3 - 5). The number of SH groups was determined to be 2 mol/mol enzyme. In the presence of 6 M urea the figure inceases to 3 mol SH/mol enzyme. In the presence of an excess of p-chloromercuribenzoate the enzyme activity decreases only partially.
Within an extended semiquantal theory we perform large-sized coupled-channel calculations involving 260 collective levels for Coulomb fission of 238U. Differential Coulomb fission cross sections are studied as a function of bombarding energy and impact parameter for several projectiles. In the Xe + U case, total cross sections are also given. We find a strong dependence on projectile charge number, PCF(180°)∼(Zp)6 in the region 50≤Zp≤92 for a fixed ratio E/ECoul, which might be helpful to separate Coulomb fission experimentally from sequential fission following transfer reactions. Since the cross sections are sensitive to the moment of inertia ⊖ at the saddle point, Coulomb fission can serve as a tool to investigate the dependence of ⊖ on elongation. The fragment angular distribution exhibits deviations from 1/sinθf which are pronounced at low incident energies. Our theory indicates that the recently measured Xe + U fission cross sections contain a major fraction of Coulomb-induced fission at E≤0.85 ECoul. NUCLEAR REACTIONS, FISSION Calculated Coulomb fission cross sections σ(Ep,θp) for 54Xe, 67Ho, 82Pb, 92U→92238U, fragment angular distribution, fission energy spectrum, mean spin value 〈Jf〉.
The theory of nucleon transfer in heavy ion reactions is formulated on the basis of the molecular particlecore model for a system consisting of two cores and one extracore nucleon. The extracore nucleon is described by the molecular wave functions of the asymmetric two-center shell model. The cores, which are assumed to be collectively excitable, are treated with vibrator-rotator models. Potentials for shape polarization are contained in the asymmetric two-center shell model and the interaction between the cores. The excitation and transfer of the extracore nucleon is induced by the radial and rotational couplings. The coupled channel equations, which include the recoil effects in first approximation, are derived in a form suitable for numerical calculations of cross sections. NUCLEAR REACTIONS Heavy ion scattering, theory of nucleon transfer, molecular wave functions, two-center shell model, collective and single-particle excitation.
Twelve genera, two of them new, are recognized in the tribe Adesmiini in southern Africa. Four new species of Epiphysa, one of Alogenius (placed in a new subgenus), two of Stenocara, one of Metriopus, and one placed in one of the new genera, are described. The genera are revised, and their distribution and relationship are briefly discussed
This Letter discusses inner-shell excitation in collisions of very heavy ions (Z1+Z2≳140) in the framework of the quasimolecular model. The importance of multistep excitations and of coupling between continuum states is demonstrated. The 1sσ vacancy probabilities resulting from coupled-channels calculations exceed perturbation theory by a factor 3-5, thus giving good agreement with recent experimental results.
This paper is a preliminary attempt to reconstruct the consonant system of Proto-East-Cushitic (PEC) , one of the four branches of the Cushitic family. Data are taken from some twenty-odd languages including unpublished material on a variety of hitherto little known languages. After discussing a number of general problems raised by the phonological comparison of the East Cushitic languages, 23 consonants are reconstructed for the inventory of the proto-language and the evidence for the reconstructions is presented in the form of cognate sets and correspondence rules which map the proto-phonemes onto the individual reflexes. The method employed is that of comparative linguistics as traditionally employed in Indo-European linguistics.
Binding energies and wave functions of inner-shell electronic states in superheavy quasimolecules with (Zp+Zt)α>1 are calculated. Ionization during a collision of very heavy ions is investigated within a molecular basis generated by the solutions of the two-center Dirac equation. Transitions to vacant bound states as well as direct excitation to the continuum are taken into account. We present theoretical values for the ionization probability as a function of impact parameter, bombarding energy, and combined nuclear charge. Our computed results are compared with recent experimental data. It is suggested that relativistic binding energies of electrons in superheavy quasimolecules can be determined experimentally via the impact-parameter dependence of ionization and the anisotropy of quasimolecular radiation.
In the present paper we develop the essential theoretical tools for the treatment of the dynamics of High Energy Heavy Ion Collisions. We study the influence of the nuclear equation of state and discuss the new phenomena connected with phase transitions in nuclear matter (pion condensation). Furthermore we investigate the possibility of a transition from nuclear to quark matter in High Energy Heavy Ion Collisions. In this context we discuss exotic phenomena like strongly bound pionic states, limiting temperatures, and exotic nuclei.
Some physical and chemical properties of the cancerostat cyclophosphamide (generic name: ENDOXAN) and its basic constituents H3PO4 and nor-N-mustard have been calculated with the help of a modified CNDO/S-method. The spectroscopic data of the H3PO4 , which is the starting-point for a corresponding calculation of cyclophosphamide, has been studied by taking account of the 3 d electron of the phosphorus. Nor-N-mustard is a very reactive compound, characterized by the ability to split off chloride ions and to act as an alkylating agent. The binding of the nor-N-mustard to the cyclic phosphate ester (cyclophosphamide) modifies the chemical reactivity of the mustard group in an essential way, and the 3d electron of the phosphorus plays an important role with respect to the excitability of the C -Cl bonds. Cyclophosphamide must be metabolized in a suitable way to develop the same alkylating activity as the nor-N-mustard. The computation of the excited states of cyclophosphamide revealed a similar term scheme as it was found by Clar in the case of the carcinogenic polycyclic hydrocarbons.
Pion-production cross sections have been measured for the reaction 40Ar+40Ca--> pi ++X at a laboratory energy of 1.05 GeV/nucleon. A maximum in the pi + cross section occurs at mid-rapidity, which is anomalous relative to p+p and p+nucleus reactions and compared to many other heavy-ion reactions. Calculations based on cascade and thermal models fail to fit the data.
Number 1 of Australasian Arachnology contains news and notes from the Australasian Arachnological Society. At present the aim of this society is that of other arachnological societies: to promote the study of arachnids, in our case especially Australasian arachnids. In time this aim may become more refined. The newsletter is intended as a means of communication between arachnologists-amateurs and professionals.
Australasian Arachnology
(1979)