bluuebunny/crossref_metadata_2025 huggingface dataset:
Is there a Metallic State in Two Dimensions?
Authors: Hamilton A. R. , Simmons M. Y. , Pepper M. , Linfield E. H. , Rose P. D. , Ritchie D. A.
Published: November 2018

This paper reviews a series of experimental results on the metallic behaviour
recently discovered in high quality, two-dimensional (2D) GaAs hole
transistors. In particular, we address the question of what has happened to
the two quantum corrections to the resistivity due to weak localisation and
weak electron—electron interactions in the so-called metallic state.
Detailed magnetoresistance data are presented just on the metallic side of the
apparent metal—insulator transition, which show that both weak
localisation (observed via negative magnetoresistance) and weak
hole—hole interactions (giving a correction to the Hall constant)
are present in the ‘metallic’ phase. The results suggest that as
T→ 0 the resistivity will stop decreasing but turn
up and tend towards infinity, in agreement with the early predictions of the
one parameter scaling theory of localisation. The implication is that, even at
high r s , there is no metallic
phase at T = 0 in two dimensions. Other
unexplained features of the anomalous ‘metallic’ state are also
discussed, such as the destruction of metallic behaviour by a parallel
magnetic field.
Density Matrix Renormalisation Group Method and Symmetries of the Hamiltonian
Authors: McCulloch Ian P. , Gulácsi Miklos
Published: November 2018

Substantial improvements in the computational effort in a density matrix
renormalisation program can be made by utilising symmetries of the
Hamiltonian. Extra quantum numbers are always desirable to include in the
calculation, since it allows the Hilbert space of the superblock to be
refined. Since the speed of the calculation is approximately
O(n 3 ) in
superblock states, the speed increase in targeting a specific total spin state
can be considerable. In this paper a new density matrix renormalisation
algorithm is presented which conserves the total spin. The general procedure
obtained works for any operator, even operators that do not commute with the
Hamiltonian.
Ro-vibrational Transition Energies and Absorption Intensities of the 1A1 States of H2O, He2O2+ and He2S2+
Authors: Hughes Sudarko, J. M. , von Nagy-Felsobuki E. I.
Published: November 2018

Variational ro–vibrational wave functions are calculated using an
Eckart?Watson Hamiltonian, which has embedded an ab initio
potential energy function. These wave functions,together with an ab initio
dipole moment function,are employed to predict transition energies and
absorption intensities. The radiative transition probability integrals are
determined using a novel adaptation of the
Harris–Engerholm–Gwinn integration scheme. The method
and solution algorithm yields results in excellent agreement with previously
determined experimental and theoretical electric dipole allowed transitions
for the 1 A 1 ground state of H
2 O. The method has also been applied to the
1 A 1 states of the helide analogs
of water, namely He 2 O 2+
and He 2 S 2+, in order to
predict their ro–vibrational transition energies and absorption
intensities, thereby facilitating their possible interstellar detection.
Study of Strain Relaxation in InAs/GaAs Strained-layer Superlattices by Raman Spectroscopy and Electron Microscopy
Authors: Gutakovsky A. K. , Pintus S. M. , Toropov A. I . , Moshegov N. T. , Haisler V. A. , Rubanov S. , Munroe P.
Published: November 2018

InAs/GaAs strained-layer superlattices (SLS) grown on a GaAs(100)
substrate were studied by both Raman spectroscopy (RS) and transmission
electron microscopy (TEM). It was shown that the interfaces inside the
superlattice are coherent, but the superlattice–substrate interface
contain an orthogonal two-dimensional network of 60° misfit
dislocations. Using these experimental data values of elastic strain in
individual layers and the average values of the residual elastic strain in SLS
were determined. The latter are approximately one order of magnitude higher
than theoretically predicted data, which suggests that the relaxation of
elastic strains was not fully complete. Subsequent annealing of these
structures led to the generation of more misfit dislocations, consistent with
further relaxation of elastic strain.
Low-Energy Electron Scattering by CS2 Molecules
Authors: Bettega Márcio H. F.
Published: November 2018

We report the integral elastic cross section for low-energy electron
scattering by CS2 molecules. To perform our calculations
we used the Schwinger multichannel method with pseudopotentials.We have found,
in a static-exchange calculation, a shape resonance around 1 eV that belongs
to the Π u symmetry.With the inclusion of
polarisation effects only in that symmetry, we show that the resonance becomes
a bound state. This result is in agreement with other results available in the
literature.
On Nonleptonic Decays of Supermultiplets
Authors: Delbourgo R. , Liu Dongsheng
Published: November 2018

By describing strong interactions between hadrons via a relativistic
supermultiplet scheme and regarding weak interactions as a perturbation
thereof, we derive expressions for nonleptonic weak decay amplitudes in terms
of constituent quark masses and CKM angles, with no other parameters.
Application of this method leads to ΔI =
dominance in some pseudoscalar meson decays if one scales down the couplings
of heavy particles by M mass factors, in keeping with
heavy quark theory expectations. However, certain B and D decay processes to
kaons are badly predicted and point to substantial soft gluon renormalisation
effects inW-quark interactions.
The Determination of Electron Trajectories in the Presence of Space Charge
Authors: Hollway DL
Published: November 2018

The analogy between space charge in an electrostatic field and current sources in an electrolytic tank is considered and methods of simulating clouds of distributed charge by discrete current sources are developed.
The Effect of Multiple Scattering on Electron Energy Loss Distributions
Authors: Hebbard DF , Wilson PR
Published: November 2018

Calculations have been performed to obtain the theoretical energy loss distributions of 1 MeV electrons traversing foils thick enough for multiple scattering to be important. A criterion has been developed and applied to previous experiments to determine the foil thicknesses for which multiple scattering has an appreciable effect on the energy loss distribution.
A Proposed Modification to the C.S.I.R.O. Mark I Computer
Authors: Swire BE
Published: November 2018

The order code of the C.S.I.R.O. Mark I computer, as described by Pearcey and Hill in their recent papers (1953a, 1953b, 1954), is already more extensive and flexible than that of any other machine of which a description has been published. It still offers some scope for expansion, however, and it is the purpose of this note to put forward one particular suggestion for the addition of an entirely new type of order. "General purpose" computers, so-called, are at present by no means so general in their application as users would desire, and broadly speaking there are two types of attack on this problem.
The Damping of Water Waves by Surface Films
Authors: Vines RG
Published: November 2018

Measurements have been made of the stilling of small water ripples by surface :films of cetyl alcohol. The damping is considerable and is somewhat in excess of that predicted by existing theories. Imperfections in the ripples induce a directed surface drift (surface mass transport), and it is possible that this is indirectly responsible for the extra damping. Under natural conditions surface films not only impede the formation of small waves but they are also very effective in damping them out.
The First Excited State of 9B
Authors: Barker FC
Published: November 2018

The energy of the ! + first excited state of 9B is derived from the measured energy of the analogue state in 9Be together with calculated values of the Coulomb displacement energy. The latter include contributions from the internal Coulomb interaction, the electromagnetic spin-orbit interaction and the different external wavefunctions in 9Be and 9B. The ! + excitation energy is predicted to be greater in 9B than in 9Be,arising from an inverted Thomas-Ehrman shift, due to the 9Be state being above the 8 Be(g.s.) + s-wave neutron threshold. This result is in conflict with a recently published calculation (Sherr and Bertsch 1985), which was based on a single-particle potential model.
Angular Distributions for 6Li(p,g)7Be
Authors: Tingwell CIW , King JD , Sargood DG
Published: November 2018

Angular distributions of y rays leading directly to the ground and first excited states in the reaction 6Li(p, y) 7Be have been measured at bombarding energies of 500, 800 and 1000 keV. The results are compared with those of previous measurements and substantial agreement is found. The results are also compared with theoretical predictions of a simple direct capture model.
Ion Densities in Low Temperature Nitrogen Plasmas
Authors: Donnelly IJ , Rose EK
Published: November 2018

A cross-section library for the electron ionisation of hydrogen and nitrogen molecules, atoms and ions has been assembled and used for the derivation of reaction rate coefficients assuming a Maxwellian distribution of electron energies. For fixed electron temperatures, the steady-state and time-dependent ionisation of nitrogen molecules have been calculated for conditions relevant to glow discharge plasmas in which the dominant recombination mechanism occurs via the plasma-wall interaction. The analysis shows that there is a threshold electron temperature below which there is no steady-state ionisation. For a small range of temperatures above this threshold there are two possible ionisation states, but at higher temperatures only the more highly ionised state persists. The dependence of the ratio of N+ to N~ ions on filling pressure, confinement time and electron density is also discussed.
Delayed Inflation of a Closed Cosmological Model Driven by the False Vacuum in Five Dimensions
Authors: Wolf C
Published: November 2018

An inflationary cosmology in five dimensions is discussed that has the unique feature that if initial conditions are tuned appropriately with the values of the unstable maximum of the Higgs potential the universe is trapped in a Lemaitre-type equilibrium point after which it expands in an exponential manner. Such a quasi-static intermediate point may be responsible for the homogeneity of the universe at late times.
Heat Conduction through Support Pillars in Evacuated Windows
Authors: Collins RE , Poladian L , Pailthorpe BA , McPhedran RC
Published: November 2018

A study has been made of the rate of heat transport through a short pillar connecting two separated plates. Three separate approaches to the problem are discussed-analytic, numerical and experimental. The results of the different methods are in good agreement, and confirm the classical result for heat flow through a short, circular contact between semi-infinite bodies. These results are of particular relevance to the design of flat evacuated glazings incorporating short support pillars.
Wave Function Collapse in Atomic Physics
Authors: Pegg DT
Published: November 2018

Wave function collapse has been a contentious concept in quantum mechanics for a considerable time. Here we show examples of how the concept can be used to advantage in predicting the statistical results of three experiments in atomic physics and quantum optics: photon antibunching, single-photon phase difference states and interrupted single-atom fluorescence. We examine the question of whether or not collapse is 'really' a physical process, and discuss the consequences of simply omitting it but including the observer as a part of the overall system governed by the laws of quantum mechanics. The resulting entangled world does not appear to be inconsistent with experience.
Observations of Atmospheric Dynamics Using Radar Techniques
Authors: Briggs BH
Published: November 2018

A surprisingly large amount of information about atmospheric dynamics can be obtained by studying the fluctuations of the amplitude and phase of radar echoes back-scattered from density irregularities. The method has been extensively used by the Atmospheric Physics Group at the University of Adelaide, and elsewhere. In the present paper these techniques are traced back to their origin in the pioneering work of J. L. Pawsey in the 1930s, and followed through to the present day. The reasons which led to the construction of the large antenna array near Adelaide (the 'Buckland Park array') are explained, and the observations which can be made with it are described. These include radar measurements of winds, turbulence and momentum flux in the height range 60 to 95 km. Plans for instrumental improvements and for future work are outlined. The paper is not intended to be a general review of the field, but rather a history of a technique and its development in the research groups with which the author has been associated.
The Three Phases of Solid Deuterated Methane
Authors: Kansal MK , Trikha SK
Published: November 2018

By using a computer simulation technique, the three phases of solid deuterated methane have been interpreted in terms of the changes in dynamical behaviour of the CD4 molecule located at the centre of a tetragonal unit cell having dimensions a = b = 5�872 A and c = 5�95 A. The central molecule is influenced by twelve nearest neighbour molecules situated at the mid-points of the sides of the unit cell. The rotational motion of the tetrahedral molecule is described by the appropriate algorithm equations, as well as by the well-known Lennard-Jones potential. The present calculations reveal two transition regions separating three distinct phases, which can be attributed to the two ,x-type transitions depicted by Clusius et al. (1937). Making use of the (dimensionless) average rotational kinetic energy corresponding to the lower transition region, (ERK)critical = 4�8, and the experimental libration frequency 6700 m-1 reported by Savoie and Fournier (1970), the transition temperature turns out to be 21�2 K, close to the experimentally observed value.
Near-threshold Behaviour of Generalised Oscillator Strengths for 2p Ionisation
Authors: Padma R , Deshmukh PC
Published: November 2018

Near the ionisation threshold, the behaviour of the generalised oscillator strength (GOS) is sensitive to the choice of the model atomic potential. In electron-impact ionisation, 'delayed maxima' of the GOS often occur near the ionisation threshold due to centrifugal barrier effects. In the present work, the sensitivity of this important effect of the centrifugal barrier to the model atomic potential has been studied using two local density atomic potentials, namely, the nonrelativistic Hartree-Slater potential and the relativistic RCB potential. Calculations have been done for electron-impact 2p ionisation of atomic oxygen, neon, aluminium, argon, iron and zinc. The GOS results for 2p ionisation of oxygen and aluminium are presented to illustrate the results.
Transport Coefficients and Velocity Distribution Function of an Ion Swarm in an AC Electric Field Obtained from the BGK Kinetic Equation
Authors: Robson RE , Makabe T
Published: November 2018

The transition to a periodic steady state for an ion swarm in a gas is investigated using the BGK model kinetic equation. Exact expressions for transport coefficients and the velocity distribution function are obtained and the latter is compared with experimental observations of ions in their parerit gases undergoing predominantly charge-transfer collisions.
Computational Aspects of the Calculation of the Leading Divergence of a Particle?Particle Ladder
Authors: Sinclair R
Published: November 2018

In order to isolate the leading divergence of a particle-particle ladder graph, we wish to study the most positive eigenvalue, and its eigenfunction, of the operator describing the addition of one rung. We discuss issues of computational efficiency associated with the setting up and solving of the resulting eigenvalue problem, with an emphasis on the use of inherent symmetries to reduce the size of the problem, and the choice of machine and algorithms appropriate for the calculation. In particular, we compare various load-balancing techniques for a problem involving a large number of independent integrals, requiring greatly differing amounts of computer time, which we have implemented on an Intel Paragon massively parallel supercomputer. We find that a stack-based parallel adaptive integration algorithm performs significantly better than a more natural recursive implementation when load-balancing is a priority.
Beyond the Variational Principle in Quantum Field Theory
Authors: CL Hollenberg Lloyd
Published: November 2018

A method of summing diagrams in quantum field theory beyond the variational Gaussian approximation is proposed using the continuum form of the recently developed plaquette expansion. In the context of >-<j} theory the Hamiltonian, H[�], of the Schrodinger functional equation H[�]\II[�] = E\II[�] can be written down in tri-diagonal form as a cluster expansion in terms of connected moment coefficients derived from Hamiltonian moments (Hn) == !V�VI[�]Hn[�JVd�] with respect to a trial state VI [�]. The usual variational procedure corresponds to minimising the zeroth order of this cluster expansion. At first order in the expansion, the Hamiltonian in this form can be diagonalised analytically. The subsequent expression for the vacuum energy E contains Hamiltonian moments up to fourth order and hence is a summation over multi-loop diagrams, laying the foundation for the calculation of the effective potential beyond the Gaussian approximation.
Physical Consequences of the Interpretation of the Skew Part of gµv in Einstein's Nonsymmetric Unified Field Theory
Authors: Voros Joseph
Published: November 2018

The electromagnetic interaction in the Einstein-Infeld-Hoffmann (EIH) equations of motion for charged particles in Einstein's unified field theory (EUFT) is found to be automatically precluded by the conventional identification of the skew part of the fundamental tensor with the Faraday tensor. It is shown that an alternative identification, suggested by observations of Einstein, Bergmann and Papapetrou, would lead to the expected electromagnetic interaction, were it not for the intervention of an infelicitous (radiation) gauge. Therefore, an EIH analysis of EUFT is inconclusive as a test of the physical viability of the theory, and it follows that EUFT cannot be considered necessarily unphysical on the basis of such an analysis. Thus, historically, Einstein's unified field theory was rejected for the wrong reason.
Meson Supermultiplet Decay Constants
Authors: Jones NR , Delbourgo R
Published: November 2018

We use a covariant supermultiplet theory to determine the primary coupling constant associated with several types of two-body meson decay. Despite the diverse range of decays considered, the primary coupling constant is surprisingly uniform. We envisage the extension of the techniques to heavy quark cases, including as preliminary examples the calculation of the D*+ and D*o total decay widths with results 57 �7�1�5 keY and 42�5�2�6 keY respectively, as well as some predictions about D� and B* radiative decays.
A Fibre Optic Sensor for High-velocity Measurements of Projectiles Driven by Hot Gases
Authors: Di Marzio Frank , Szajman Jakub , Mazzolini Alex
Published: November 2018

A fibre optic sensor system for the measurement of the velocity of projectiles propelled by hot gases has been developed. It was found that fibre optic techniques have significant advantages over conventional breakwire methods in this electromagnetically noisy environment. A simple passive fibre system produced both accurate and reliable measurements of projectile velocities which, in this study, were in the range 1-3 km s-l. In addition, by using a number of fibres at different positions along the projectile path, the average velocity of the projectile can be determined at several points, and a velocity profile for the projectile motion obtained.
Chaos and Its Impact on the Foundations of Statistical Mechanics
Authors: P Morriss Gary , Rondoni Lamberto
Published: November 2018

In this work we present a brief derivation of the periodic orbit expansion for simple dynamical systems, and then we apply it to the study of a classical statistical mechanical model, the Lorentz gas, both at equilibrium and in a nonequilibrium steady state. The results are compared with those obtained through standard molecular dynamics simulations, and they are found to be in good agreement. The form of the average using the periodic orbit expansion suggests the definition of a new dynamical partition function, which we test numerically. An analytic formula is obtained for the Lyapunov numbers of periodic orbits for the nonequilibrium Lorentz gas. Using this formula and other numerical techniques we study the nonequilibrium Lorentz gas as a dynamical system and obtain an estimate of the upper bound on the external field for which the system remains ergodic.
Hybrid model for drift waves in fully three-dimensional plasmas: Theory and applications.
Authors: Lewandowski J. L. V.
Published: November 2018

A novel fluid/gyro-kinetic hybrid model to study drift waves in
low-pressure stellarator plasmas is presented. The ion population is modeled
with the collisionless gyro-kinetic equation and the electron population is
described using fluid equations. The model equations are written in
straight-field-line coordinates and are valid for any magnetic configuration
with closed, nested magnetic surfaces. The geometrical effects which enter the
final eigenmode equations are derived and discussed in some detail. The
numerical method used to solve the coupled, time-dependent,
along-the-field-line equations is described. The geometrical effects are
discussed in some detail. Numerical calculations are carried out for a
three-field period toroidal heliac with small global magnetic shear.
A Generalised Linear Response Theory applied to the Dielectric Function of Coulomb Systems
Authors: Reinholz H.
Published: November 2018

A generalised linear response theory is used to derive the dielectric function
at arbitrary wave numbers k and frequencies
w for interacting quantum systems. The connection to
thermodynamic Green functions allows the systematic perturbative treatment
going beyond RPA and treating local field corrections as well as the inclusion
of collisions on the same footing. Emphasis will be on the demonstration of
the formalism. Results will be presented for the three-dimensional as well as
two-dimensional case of an interacting electron gas. In the long-wavelength
limit, a Drude-type expression with frequency dependent relaxation time is
given bridging the theories of dielectric function and electrical
conductivity.
Monopole in the Dilatonic Gauge Field Theory
Authors: Karczewska D. , Manka R.
Published: November 2018

A numerical study of static, spherically symmetric monopole solutions coupled
to the dilaton field, inspired by the Kaluza–Klein theory with
large extra dimensions is presented. The generalised
Prasad?Sommerfield solution is obtained. We show that the monopole
may also have the dilaton cloud configurations.
Unusual Ultrastructural Features of the Chloroplast-Chromoplast Transformation in Solanum luteum Fruit
Authors: Simpson D.J , Baqar M.R , Lee T.H
Published: November 2018

The ultrastructure and pigment composition have been followed in the plastids of the ripening fruits of yellow- and orange-fruited cultivars of S. luteum. Chloroplasts of green fruit transform into globular chromoplasts containing large plastoglobules, phytoferritin deposits, and lamellae. Ripe yellow fruit retain some chlorophyll, and have carotenoids typical of photosynthetic tissue. Ripe orange fruit contain �-carotene and lutein and their 5,6-epoxy derivatives, and also cis-lutein, neoxanthin, and a trace of neochrome. The ultrastructure of some of the transforming chloroplasts of this fruit is similar to that of plastids from the xan-a*63 barley mutant in that they containextensive lamellar tubules. The unusual ultrastructure of the plastoglobules and the formation of 'thylakoid centres' are discussed.
The Path of Carbon in CAM Plants at Night
Authors: Sutton B.G
Published: November 2018

Following demonstrations that malic acid synthesis in crassulacean acid metabolism (CAM) plants at night requires only the carboxylation of phosphoenolpyruvate, glycolysis has been presumed to supply this substrate. This study has examined the path of carbon in CAM plants at night to establish the involvement of intermediary pools of metabolites in other processes, and to define characteristics of the pathway which are likely to be involved in its regulation. In both Bryophyllum tubiflorum Barv. and Kalanchoe daigremontiana Hamet et Perrier, carbon loss from starch was insufficient to account for malic acid gains. Quantitative examination of the pool sizes of various carbohydrates and malic acid during the dark showed that starch was only part of a larger glucan pool which was the carbon source material for phosphoenolpyruvate supply. Observations of the utilization of 14C-labelled glucan in a CAM plant in the dark supported the role of this compound as primary carbon donor for acid synthesis. The mainstream of carbon flow was shown not to pass through the free sugar pools, and it was also proposed that malic and citric acids were able to exchange carbon via tricarboxylic acid cycle reactions. Examination of the influence of temperature on the glucan-malic acid relationship suggested that the depressed malic acid levels accumulated after nights at higher temperature were due to regulation of the reactions concerned with acid synthesis from glucan.
Effects of Ultraviolet Radiation on the Plasma Membranes of Chara corallina. II* The Action Potential
Authors: Doughty C.J , Hope A.B
Published: November 2018

When cells of C. corallina were irradiated with 254 nm ultraviolet light, the action potential across
the plasmalemma was unaffected in its peak height, but its duration (measured at half-peak height)
was increased, more so as the dose was varied between 1500 and 6000 J m-2. The action potential
across the tonoplast was reduced in peak height and increased in duration by U.V. The effects were
slowly reversible.
The effect of 285 nm u.v., effective in depolarizing the resting potential difference, was to decrease
the peak of the plasmalemma action potential while leaving the duration virtually unaffected. The
results are interpreted as revealing differential effects on gating mechanisms determining the duration,
and on transient membrane permeability to chloride (and possibly potassium) determining the peak,
of the action potential. Because of the differential wavelength effects, these two membrane properties
are postulated to be mediated by molecules which act as distinctive targets to the two wavelengths.
Proton Translocations in Isolated Spinach Chloroplasts after Single-turnover Actinic Flashes
Authors: Hope A.B , Morland A
Published: November 2018

Proton movements were monitored with cresol red and neutral red. Absorbance changes of these dyes following actinic flashes were measured both for the steady state and for sequences of 6-9 flashes given to separate dark-adapted suspensions of chloroplasts. The cresol red changes corresponded to a steady-state proton uptake (�H*+ss) of 0.0015-0.0017 mol H+/mol Chl per flash (ferricyanide as electron acceptor) or 0.0031 mol H+/mol Chl per flash (methyl viologen). Assuming 600 Chl per electron transport chain, these uptakes corresponded to H+/e- = 1 or 2 respectively. In flash sequences with ferricyanide, a minimum of about 0.6 �H*+ss was noted after flash No. 3. Controls, and considerations of the partitioning of unprotonated neutral red into the thylakoid membrane phase, strongly indicated that neutral red was responding to an acidification of the intrathylakoid aqueous phase. The steady-state signal was interpreted as 2 H+ deposited per electron transport chain per flash (H+/e- = 2), one proton from the oxidation of water and one from the oxidation of plastoquinone. Patterns of proton deposition following sequences of flashes and their change upon adding dibromothymoquinone suggested that (a) protons are produced one at a time in the advance of the 'S-states' (Z*n+ � Z(n+1)+ ); and (b) the precursor to the plastoquinone pool, B, is a special plastoquinone, requiring 1 e- and 1 H+ for its initial reduction but passing on to the plastoquinone pool 2 e- upon the next flash. The proton deposition on flash No. 1 corresponded to a small proportion of reduced B in dark-adapted chloroplasts, as previously postulated.
The Action Potential in Chara coraliina II.* Two Activation-Inactivation Transients in Voltage Clamps of the Plasmalemma
Authors: Beilby M.J , Coster H.G.L
Published: November 2018

Voltage-clamp experiments over a wide range of clamp potentials were made with cells of C. corallina using a fast voltage-clamp apparatus. Clamps of the plasmalemma potential in the range - 170 mV to - 70 mV revealed a large transient inward current which followed the usual chloride current transient hitherto described in the literature. This additional component decreased in amplitude and occurred earlier in the clamp as the clamp potentials were made more positive up to ~ -70 mV. For clamp potentials > - 50 mV, a large, prompt, outward current appeared. The additional current transients could not be observed in vacuolar potential clamp experiments, except at clamps � - 10 mV.
The effects of changes in the external Cl- and Ca�+ concentrations with plasmalemma clamps at various potentials suggest that the additional transient here reported consists of a flow of Ca�+ ions and also reaffirms the identification of the other transient with a flow of Cl- ions.
Reversal of the additional current transient when the clamp potential is sufficiently large (i.e. at large depolarization), places the equilibrium potential of the ionic component responsible for this transient at - 50 mV (� 20 mV).
Estimates, based on this equilibrium potential, of the cytoplasmic Ca�+ concentration yield unrealistic values. Possible answers to this dilemma are discussed.
Amino Acid Sequence of the Small Subunit of Ribulose-1,5-Bisphosphate Carboxylase from Spinach
Authors: Martin P.G
Published: November 2018

The complete amino acid sequence of the small subunit of ribulosebisphosphate carboxylase from spinach has been determined. There are 120 amino acids. The N-terminus of the protein is frequently blocked. There is a tyrosine-proline substitution at position 91 and the average molecular weight of the two forms is 13 897. The interest of the sequence data for students of physiology and evolution is discussed.
Regulation of Turgor Pressure in Marine Algae: Ions and Low-molecular-weight Organic Compounds
Authors: Kirst G.O , Bisson M.A
Published: November 2018

Seventeen species of thalloid or giant-celled marine algae representing the three major classes, Chlorophyceae, Rhodophyceae and Phaeophyceae maintain turgor pressure constant over the range of 470-1860 mosmol/kg external osmotic concentration. This is achieved by changing internal concentrations of Na+, K+ and Cl-. Three different groups can be distinguished: (1) species with high Na+ ; (2) those with high K+; and (3) algae with both cations in about equal amounts. In general, a Cl- pump seems to be involved in turgor regulation. There is no correlation between ion composition and taxonomic class. The concentration of low-molecular-weight organic compounds also changes during regulation. As a rule, these compounds are the main photosynthetic products and are probably located in the cytoplasm.
Cycloheximide Inhibition of Cytokinin-dependent Protein Synthesis: Correlation with Betacyanin Synthesis
Authors: Elliott D.C , Koltunow A
Published: November 2018

Cytokinin-dependent betacyanin accumulation in Amaranthus trlcolor half-seedlings (cotyledons plus
5-mm hypocotyls) can be detected after a lag period of about 6 h. A significant (P<O.01) promotion
by cytokinin of [3H]leucine incorporation into protein was observed at 5-7 h. It is concluded that
the cytokinin-induced biological response was subsequent to or at the same time as the effect on
protein synthesis and therefore could be dependent on it, a conclusion that is strengthened by the
correlation between the effects of cycloheximide on the two processes. Cycloheximide preferentially
inhibits cytokinin-dependent protein synthesis as compared to the effect of the inhibitor on the basal
rate.
Adenylate Concentrations in Chara: Variability, Effects of Inhibitors and Relationship to Protoplasmic Streaming
Authors: Reid R.J , Walker N.A
Published: November 2018

The concentrations of ATP, ADP and AMP In Chara vary considerably depending on the culture
conditions. The ranges of cytoplasmic concentrations were: ATP, 1 6-3 4 mM; ADP, 0 1-1 1 mM;
AMP <O 6 mM. The ATP concentration was lower in the dark than in the light by 5-25%. The
cytoplasmic concentration of inorganic phosphate in cells from one culture was 21 2 mM. From these
values AGATp lies in the range 47-52 kJ mol-I.
Lowering of the ATP concentration by metabolic inhibitors CCCP (carbonyl cyanide mchlorophenylhydrazone),
DCCD (N,N'-dicyclohexylcarbodiimide) and DCMU (3-(3-chloropheny1)-1,
I-dimethylurea) was associated with almost parallel changes in the rate of protoplasmic streaming.
The use of streaming rate as an in vivo indicator of ATP status is discussed.
The results are consistent with the participation of adenylate kinase in the regulation of adenylate
concentrations.
Oscillation of Membrane Currents During the Action Potential in Chara corallina: Modification and Significance for Repolarisation
of the Membrane Potential and Salt Sensitivity
Authors: Kourie J.I
Published: November 2018

Depolarising voltage-clamp steps in C. corallina induced membrane currents which differ
from those of C. inflata in two aspects: (1) The absence of a 'hump', i.e. a transient outward current,Io(max) which is present in C. inflata, and (2) the presence in C, corallina of a voltage-dependent current oscillation, i.e. a succession of decaying peaks.
The peaks of the oscillating transient inward current, Ii(max), were voltage dependent and sensitive to
block with 9-anthracenecarboxylic acid (9-AC). The oscillating current is carried by C1- and its time
course is determined by the activation and inactivation kinetics of C1- channels.
Extracellular NaCl delayed current activation, induced a voltage-dependent increase in Ii(max) and a
decrease in the steady-state outward K+ current, Is. NaCl increased the occurrence of oscillation and
enhanced the amplitude of the oscillating current. Extracellular sorbitol induced an overall reduction in
Ii(max) and had virtually no effect on Is. I suggest that the enhancement of the oscillating transient inward
CI- current, Ii(max), by NaCl is due to ionic effects of NaCl rather than to its osmotic effects.
Program for Aboriginal and Torres Strait Islander People in the Goulburn-Murray Region: Development and Risk Factor Screening at Indigenous Community Organisations
Authors:   The Heart Health Project Steering Committee Contributors: Leeandra Aitken, Anderson Ian , Atkinson Vicki , D Best James , Briggs Paul , Calleja Julie , Charles Sharon , Doyle Joyce , Mohamed Justin , Patten Rochelle , Rowley Kevin , Simmons David
Published: November 2018

The Heart Health Project was developed in partnership between Aboriginal health and social organisations in the Goulburn-Murray region and university departments. The aims included screening for cardiovascular disease (CVD) risk factors, and evaluating community-directed interventions. We describe the development of the Heart Health Project and the results of risk factor screening among employees (n=66) of Aboriginal organisations during 2003-04. Screening identified few new cases of overt hypertension, diabetes or hypercholesterolaemia, but did find a large proportion of the survey sample who smoked, had evidence of periodontal disease or who had ?high normal? levels of risk factors at a relatively young age, placing them at risk of developing overt disease. Barriers to diet and exercise behaviours thought to protect against CVD were documented. While appropriate planning made clinical follow-up relatively straightforward, effective referral of at-risk people to primary prevention programs was more difficult. The barriers to making diet and exercise changes need consideration in designing interventions for primary prevention of CVD, as does the importance of promoting heart health in a culturally relevant way. This can be achieved through community direction but long-term support for partnerships and intervention programs is required.
End-of-life Care of Aboriginal Peoples in Remote Locations: Language Issues
Authors: McGrath Pam , Holewa Hamish
Published: November 2018

To date, there is scant research literature that explores the provision of end-of-life care to Aboriginal peoples in Australia. In particular, there is a lack of published research available on issues at the interface of Aboriginal languages and English during palliative care. The complexity and importance of the issue for palliative care provision, however, is demonstrated by the fact that in Australia, Aboriginality is itself a very broad category, containing many distinct language groups and subcultures. Thus, although to date there is some mention of the problems associated with language in the literature, there is scant research on the topic of the provision of palliative care to Aboriginal peoples in remote areas. The following findings from a recent two-year National Health and Medical Research Council (NHMRC) study are provided to address this hiatus. The findings provide insights on the impact of language difference on palliative care practice for Aboriginal peoples in the Northern Territory of Australia.
Is a Chronic Disease Self-Management Program Beneficial to People Affected by Cancer?
Authors: Beckmann Kerri , Strassnick Kathriye , Abell Liz , Hermann Joanne , Oakley Barry
Published: November 2018

Randomised trials of the Chronic Disease Self-Management Program (CDSMP) have shown improvements in health outcomes for people with arthritis, diabetes, heart disease and lung disease. The potential benefits of the CDSMP for people with cancer have not been researched, even though they can experience "chronic" symptoms after treatment. This paper reports on a pilot study conducted by The Cancer Council South Australia to determine whether the CDSMP was relevant and beneficial to people affected by cancer. Feedback was obtained via semi-structured telephone interviews with participants 4-6 weeks after the conclusion of the course. Most participants felt that the course was relevant to their cancer experience. Mixing with others who had experienced cancer appeared to be a key aspect of the program. Sharing experiences helped to break down their sense of isolation, and normalise the cancer experience: "I wasn't the only one who wasn't coping". Other benefits included gaining motivation to improve their health and wellbeing, a sense of regaining control and a new-found confidence to achieving one's goals. Participants beyond the acute treatment phase appeared to benefit more from the program. This community-based program may bridge the gap for people who are adjusting after cancer treatment is completed.
Mood Changes in Weeks 2 and 6 of a Graduated Group Walking Program in Previously Sedentary People with Type 2 Diabetes
Authors: D O'Halloran Paul
Published: November 2018

Exercise-induced mood improvements are well documented in relatively young and active populations. However, it is not clear if older sedentary people with chronic illnesses such as type 2 diabetes also experience these benefits. This is particularly important given that people with type 2 diabetes are not sufficiently active and mood improvement is a potentially important motivator to exercise. The aim of the present study was to examine the effects of group walking on mood change in a sample of previously sedentary people with type 2 diabetes who were undertaking a six-week walking program. A multidimensional mood scale was utilised to assess the mood of 24 people aged 40-65 prior to and following sessions of supervised group walking on two occasions: across a 20-minute walk during week 2 of the program; and across a 40-minute walk during week 6 of the program. Results revealed improvements in positive well-being after both sessions of walking, no change in psychological distress, and increases in fatigue after the 40-minute walk. These findings could be useful to people who develop group-walking programs designed to facilitate regular exercise in people with type 2 diabetes.
Corrigendum to: Hypoxia limits mouse follicle growth in vitro
Authors: Connolly J. M. , Kane M. T. , Quinlan L. R. , Dockery P. , Hynes A. C.
Published: November 2018

Ovarian follicle culture is useful for elucidation of factors involved in the regulation of follicular function. We examined the effects of gas phase oxygen concentration, an oil overlay, serum type and medium supplementation with FSH, insulin–transferrin–selenium (ITS) and I-ascorbic acid on cultured preantral mouse follicle growth in a spherical, non-attached follicle culture system. Follicle growth in 5% oxygen was significantly (PPP>0.05) affected by an oil overlay, ITS supplementation or serum type. Culture in medium with 5% mouse serum, 1 IU mL–1 FSH, 25 μgmL–1 l-ascorbic acid and 20% oxygen without an oil overlay supported the growth of follicles to a maximum diameter of 380 μm in 6 days. Compared with mature preovulatory mouse follicles in vivo that often have diameters >500 μm within the same time frame, in vitro-grown follicles clearly exhibit limited growth. Thus, adequate oxygenation is an essential factor in the process of optimising follicle growth.
Effects of testosterone and prolactin on steroidogenesis in post-ovulatory cumuli oophori and on in vitro oocyte fertilisation in the rat
Authors: Starowicz Agnieszka , Galas Jerzy , Duda Małgorzata , Tabarowski Zbigniew , Szołtys Maria
Published: November 2018

The main objective of these studies was to determine the in vitro effects of prolactin (PRL) and testosterone (T) on steroidogenic function in post-ovulatory cumuli oophori containing unfertilised (ufCOCs) or fertilised (fCOCs) oocytes and to determine the differences between ufCOCs and fCOCs. In vivo, progesterone (P4) content was distinctly higher in isolated ampullae containing ufCOCs than in those containing fCOCs. Moreover, the expression of androgen (ARs) and prolactin (PRL-Rs) receptors was distinctly higher in ufCOCs than in fCOCs. Also, in vitro P4 profiles were generally higher in incubated ufCOCs, which had very high secretion rates of this steroid, especially after treatment with PRL+T. Testosterone significantly increased P4 levels only in incubated fCOCs, while the anti-androgen dihydroxyflutamide (2-Hf) markedly decreased P4 levels in both ufCOCs and fCOCs. Among post-incubation ufCOCs fertilised in vitro, the highest fertilisation rate was observed for oocytes in ufCOCs exposed to PRL+T, while those incubated with 2-Hf or T+2-Hf were not fertilisable. These studies establish differences in steroidogenic function and expression of ARs and PRL-Rs between post-ovulatory ufCOCs and fCOCs, with higher concentrations of P4 being observed in the microenvironment of ufCOCs. PRL+T stimulated P4 production by ufCOCs and increased in vitro fertilisation rate.
Methylation mechanisms and biomechanical effectors controlling cell fate
Authors: Brevini Tiziana A. L. , Manzoni Elena F. M. , Gandolfi Fulvio
Published: November 2018

Mammalian development and cell fate specification are controlled by multiple regulatory mechanisms that interact in a coordinated way to ensure proper regulation of gene expression and spatial restriction, allowing cells to adopt distinct differentiation traits and a terminal phenotype. For example, cell potency is modulated by changes in methylation that are under the control of methyltransferases and ten–eleven translocation (TET) enzymes, which establish or erase a phenotype-specific methylation pattern during embryo development and mesenchymal to epithelial transition (MET). Cell plasticity is also responsive to extracellular factors, such as small molecules that interact with cell fate definition and induce a transient pluripotent state that allows the direct conversion of an adult mature cell into another differentiated cell type. In addition, cell-secreted vesicles emerge as powerful effectors, capable of modifying cell function and phenotype and delivering different signals, such as octamer-binding transcription factor-4 (Oct4) and SRY (sex determining region Y)-box 2 (Sox2) mRNAs (implicated in the preservation of pluripotency), thus triggering epigenetic changes in the recipient cells. In parallel, mechanical properties of the cellular microenvironment and three-dimensional rearrangement can affect both cell potency and differentiation through marked effects on cytoskeletal remodelling and with the involvement of specific mechanosensing-related pathways.
Post-fertilisation sperm mitophagy: the tale of Mitochondrial Eve and Steve
Authors: Sutovsky Peter , Song Won-Hee
Published: November 2018

Preformationist William Harvey’s proclamation of everything live coming from an egg still holds true for mammalian mitochondria and mitochondrial genes. At fertilisation, mitochondria carried into the oocyte cytoplasm by the spermatozoon are sought out and destroyed, leaving only oocyte mitochondria to propagate their mitochondrial (mt) DNA to offspring. This clonal inheritance mode, the ‘mitochondrial Eve’ paradigm, is mediated by oocytes’ resident proteolytic, organelle-targeting mechanisms, including the substrate-specific ubiquitin proteasome system and the autophagic machinery for bulk protein and organelle degradation. Ubiquitination of sperm mitochondria within the cytoplasm of the fertilised oocyte was initially discovered in mammals. More recent studies in Drosophila and Caenorhabditis elegans implicated the ubiquitin-binding autophagy protein sequestosome 1 (SQSTM1) as the early adaptor channelling ubiquitinated sperm mitochondria towards the autophagic machinery. Downstream receptors include microtubule-associated protein 1 light chain 3α (LC3) and GABA type A receptor-associated protein (GABARAP). Among mammals, the domestic pig is the ideal mammalian model of mitochondrial inheritance because of rapid sperm mitophagy at the 1-cell stage of embryo development. Primary recognition of sperm mitochondria by SQSTM1 inside the porcine zygote is followed by GABARAP-containing autophagophore formation, and contributed to by valosin-containing protein (VCP), a 26S proteasome-presenting protein dislocase. Consequently, coinhibition of SQSTM1–GABARAP and VCP activities in the porcine zygotes, resulting in 2- to 4-cell embryos carrying intact sperm mitochondrial sheaths, revived the moniker of ‘Mitochondrial Steve’. Further work will identify the determinants of species specificity of sperm mitophagy and explain the interplay and possible consequences of a mismatch between clonal mitochondrial genome and biparentally inherited chromosomal genes encoding for structural mitochondrial proteins and transcription factors. By better understanding sperm mitophagy and its potential failure, we may be able to alleviate mitochondrial disease and early pregnancy loss in livestock and improve their fitness, reproduction and ability to pass favourable production traits to offspring.