bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Progesterone Alone and in Combination with either Corticosterone, 17ß-Estradiol or Insulin on Prolactin-stimulated Fatty Acid Synthesis in Mammary Explants from Pseudopregnant Rabbits
Authors: Martyn P , R Falconer I
Published: November 2018

Progesterone up to 15�9 ,u.mol/I progressively suppressed prolactin-stimulated fatty acid synthesis in cultured mammary explants from II-day pseudopregnant rabbits, but did not influence the proportion offatty acids of medium chain length (C80-C12 ;O). Greater sensitivity to progesterone inhibition was observed at the low end of the ranges of corticosterone (29 nmol/I) and insulin (4�2 nmol/I) concentrations in the culture medium, which suggests an interaction between the hormones. A range of from 0�0001 to 10 ,u.mol/I of 17 {3-estradiol concentrations had no effect on prolactin-stimulated fatty acid synthesis in the presence or absence of progesterone.
Essential Fatty Acids in the Fetal and Newborn Lamb
Authors: Rajion MA , McLean JG , NP Cahill R
Published: November 2018

The concentrations of linoleic and linolenic acids and their metabolites in the liver, kidney, brain, erythrocytes and plasma of fetal lambs at various stages of gestation, and of newborn and 2-week-01d suckled lambs was determined. Throughout gestation the fetal tissues, erythrocytes and plasma all contained low levels of linoleic and linolenic acids together with consistently high levels of their long-chain polyunsaturated metabolites. The triene : tetraene (eicosa-5,8, 11-trienoic acid/arachidonic acid) ratio was always 0 . 4 or less except at birth when it reached 0 . 6 in liver and 0 . 9 in plasma. Milk intake significantly increased the linoleic and linolenic acid levels in the lamb by 2 weeks after birth. These results show that the developing fetal lamb should not be regarded as being deficient in essential fatty acids, as suggested by previous investigators. It is proposed that the total metabolites of linoleic and linolenic acids are the most appropriate measure of the essential fatty acid status of the fetal lamb.
Insulin, Glucagon, Pancreatic Polypeptide Hormone and Somatostatin in the Goat Pancreas: Demonstration by Immunocytochemistry
Authors: Reddy S , Elliott RB
Published: November 2018

Insulin, glucagon, pancreatic polypeptide hormone (PP) and somatostatin immunoreactive cells were demonstrated in the islet of the goat pancreas by the immunofluorescence procedure. Islet cells showing immunostaining for the hormones appeared to have a characteristic distribution. The demonstration of PP and somatostatin within the pancreas of the goat suggests they may be significant in modulating intra- and extra-islet function in this ruminant species.
Seasonal Changes in LH Secretion in Normal Ewes and Ewes which Grazed Oestrogenic Clover
Authors: Chamley WA , Cfarkee IJ , Moran AR
Published: November 2018

Plasma luteinizing hormone (LH) concentrations were measured in normal (control) Corriedale x Merino (comeback) ewes and in clover-infertile comeback ewes which had grazed oestrogenic Yarloop clover (Trifolium subterraneum L. cv. Yarloop) for more than 4 years. Plasma LH concentrations were measured in samples taken at 20-min intervals for 6 h during the dioestrous stage of the oestrous cycle in the breeding season (BS) and during the anoestrous season (AS). In the control ewes during BS, transitory elevation in plasma LH concentration (pulses) occurred, reflecting secretory episodes, with a frequency of one per 5 �2 h. This frequency fell to one per 16�5 h during the anoestrous season. In clover-infertile ewes, LH pulses occurred with a frequency of one per 4�5 h during BS and one per 4�9 h during AS (difference not significant).
Biochemical Characterization for Identification of Ovine Sarcosporidia
Authors: Ford GE
Published: November 2018

Electrophoretic variants of enzymes from 100 individual macroscopic sarcocysts from sheep carcasses were examined to see if they could serve as genetic markers for the identification of ovine sarcosporidia. Of the 31 enzymes screened, 12 that represented single genetic loci were tested. There were two patterns of isoenzyme mobility, which differed at. 7 out of 12 of the loci being studied, and corresponded to enzymes from either 'fat' or 'thin' cysts, indicating that these two sarcocyst types may be considered quite different species. In a parallel study, extracts of microscopic sarcocysts digested from sheep heart muscle were compared with those from macroscopic sarcocysts and found to have a distinct electrophoretic isoenzyme profile for each of four loci.
Use of a Styrene-Maleic Anhydride Copolymer as an Adjuvant with Testosterone-Serum Albumin Immunogens and its Application to Increasing Ovulation Rate in the Ewe
Authors: Wong MSF , Hoskinson RM , COX RI , O Hawthorne D , Solomon DH , Hinks NT , Donnelly JB
Published: November 2018

A synthetic poly(styrene-maleic anhydride) copolymer of average molecular weight 470000 potentiated a testosterone-binding antibody response during immunization of sheep with immunogenic testosterone- 3-carboxymethyloxime-serum albumin conjugates.
Composition of Wax Made by the Australian Stingless Bee Trigona australis
Authors: V Milborrow B , Kennedy JM , Dollin A
Published: November 2018

Analysis of the nest material of T. australis by gas chromatography/chemical ionization-mass spectrometry showed the wax to comprise a hydrocarbon fraction (90%), esters (6%) and free acids . (4%). The major saturated hydrocarbons were C27, C31 and C33 with C2S and C29 being less abundant and C23 and C 3S being present in small amounts. Traces of the intermediate, even-numbered homologues were also found. Hydrocarbons (C31o C 33 and C 3S) which contained one double bond were also present and traces of the diene C3S were detected. The ester fraction did not contain compounds identical with those in beeswax made by the honeybee Apis melli/era and the acid fractions were also quite different. T. australis wax contained the following, saturated free acids: CIO (trace), C12, C14, C16, CIS and C20, monoenoic and dienoic CIS and C 20 and traces of the trienoic CIS. The wax of T. australis is colourless but the brown colour of the nest material derives from the inclusion of masses of pollen (Eucalyptus sp.) and solid material from the inside of the nest tree. The solid residue comprised between 12 and 30% by weight.
Genetic Architecture and Adaptation: Quantitative Analysis of Sheep and Refuse Tip Populations of the Australian Sheep Blowfly, Lucilia cuprina
Authors: Clarke GM , McKenzie JA
Published: November 2018

Phenotypic differentiation between geographic areas and between sheep and adjacent refuse tip populations was assessed by quantitative analysis of population samples of L. cuprina from New South Wales (Lismore) and Victoria (Mansfield). In addition the genetic structure of populations has been defined and compared by biometrical analysis techniques. For all morphological and fitness characters examined significant phenotypic differentiation was observed both between geographic localities and between sheep and non-sheep populations of each locality. Diallel analysis of the populations revealed architectural differences between sheep and non-sheep populations for both fecundity and egg hatchability. Sheep populations only, regardless of locality, displayed dominant gene effects on these fitness traits. The results suggest that refuse tip populations may be other than transients and that the differentiation may reflect differing patterns of adaptation and history of selection of the populations. The relevance of such differentiation to the successful establishment of a chemical and/or autocidal control zone is considered.
Additive and Heterotic Genetic Effects in the Haplo-diploid Honeybee Apis Mellifera
Authors: Oldroyd BP , Moran C
Published: November 2018

Nine lines of honeybees were used to form a 9 x 9 partial diallel cross. Hamuli number was determined for samples of worker offspring. One set of workers was reared in non-maternal colonies which had been made uniform, as far as possible, with respect to colony strength (number of workers), while another set was sampled directly from the combs of each maternal colony. Combining ability analysis of variance revealed significant additive and non-additive genetic effects for both sets of data, regardless of whether inbred parentals were included or excluded from the analysis. Uniform rearing removed average heterosis and reciprocal effects.
Metrical Characters in Parallel-grown Subpopulations of Barley Composite Cross Five
Authors: Luckett DJ , Sharif AL
Published: November 2018

Subpopulations derived from Composite Cross Five (CCV) were grown in parallel for six generations. Comparisons of an early and a late generation for two populations were made in the glasshouse and the field for four quantitative characters using random samples of individuals from retained bulk material and inbred lines. Considerable genetic change was detected. The populations moved towards later flowering, taller, higher-yielding plants with a marked loss of individuals that exhibited erect early growth habit. The genetic control of flowering time in the glasshouse included a major locus whose effect in the field was greatly reduced. The alternative explanations of hitch-hiking and multilocus selection were not fully resolved.
Stimulation of the Hypothalamic?Pituitary?Adrenal Axis and Inhibition of Growth Hormone Release via Increased Central Noradrenaline Neuronal Activity by Urethane Anaesthesia in the Rat: Blockade by Clonidine
Authors: Smythe GA , Gleeson RM , Stead BH
Published: November 2018

Computerized gas chromatography-mass spectrometry was used to measure precisely the hypothalamic levels of noradrenaline (NA), dopamine and serotonin together with those of their major neuronal metabolites 3,4-dihydroxyphenylethyleneglycol (DHPG), 3,4-dihydroxyphenylacetic acid and 5- hydroxyindoleacetic acid in normal male rats 45 min after stimulation of hypothalamic-pituitaryadrenal function by urethane (1� 3 g/kg) administration. Urethane treatment resulted in�a significant elevation of central noradrenergic neuronal activity (NNA) as assessed from marked rises in hypothalamic DHPG concentrations and the ratio (DHPG/NA). At the same time there was significant stimulation of ACTH and corticosterone release and inhibition of growth hormone release. These hormonal and central effects of urethane (but not anesthesia) were inhibited when the C\(Tagonist clonidine (150 Itg/kg) was co-administered. Urethane had no major effect on hypothalamic dopamine or serotonin status. We propose that the release of ACTH and the suppression of growth hormone release following urethane anaesthesia is a result of activation of central NNA and suggest that the hormonal responses are mediated via hypothalamic noradrenergic facilitation of corticotrophin releasing factor and somatostatin release to the anterior pituitary.
Current Topics in Artificial Insemination of Sheep
Authors: Evans G
Published: November 2018

There have been developments in several aspects of artificial insemination (AI) in recent years, some of which have been directly responsible for proliferation of AI in the sheep-breeding industries of several countries. The most notable advances have probably been associated with the development of intrauterine insemination by laparoscopy. There is potential for refinement of some of the related techniques, particularly in the area of control of ovulation and definition of appropriate times and optimum doses of spermatozoa for insemination. It is unlikely that laparoscopic AI will be developed sufficiently that it will become readily affordable, and therefore widely practised, by commercial producers.
Embryo Manipulation in Research and Animal Production
Authors: Shelton JN
Published: November 2018

Research in developmental biology has resulted in techniques to accelerate changes in gene frequency and to interfere directly in the genome. Procedures already in use or being adapted to livestock include embryo transfer, chimera production, embryo splitting, gene transfer and nuclear transplantation. Experiments with mouse embryos are revealing the principles governing embryonic development and differentiation and illustrate the need for these investigations to be extended to embryos of livestock. The optimal combination of these technologies in animal production strategies will depend upon further research and the role of animal products in society.
Water-to-air transfer of perfluorinated carboxylates and sulfonates in a sea spray simulator
Authors: Reth Margot , Berger Urs , Broman Dag , Cousins Ian T. , Nilsson E. Douglas , McLachlan Michael S.
Published: November 2018

Environmental contextPerfluorinated alkyl acids are found in the remotest parts of the world, but it is still not known how they get there. By using a laboratory sea spray simulator, it is shown that these compounds are efficiently transferred from water to air. This indicates that perfluorinated alkyl acids could be transported long distances as a result of breaking waves ejecting them into the atmosphere.
AbstractOne hypothesis for the origin of perfluorinated alkyl acids, their salts and conjugate bases (here collectively termed PFAAs) in the atmosphere is transfer from the surface ocean by sea spray, the mechanistic explanation being that the surface active properties of PFAAs result in their enrichment on the surface of bursting bubbles. The water-to-air transfer of C6–C14 perfluorocarboxylates (PFCAs) and C6, C8 and C10 perfluorosulfonates (PFSAs) was studied in a laboratory scale sea spray simulator containing tap water spiked with PFCAs and PFSAs. The sequestration of the PFAAs out of bulk water and to the air–water surface was shown to increase exponentially with the length of the perfluorinated alkyl chain. Volatilisation of the PFAAs from an aqueous solution in the absence of spray resulted in less than 1 % transfer to the atmosphere during the experiment. In the presence of spray the transfer rate from water to air increased by up to 1360 times. The enhancement was dependent on the PFAA chain length, with the C6 carboxylate showing an enhancement of a factor of 37, the C7 carboxylate an enhancement of 320, whereas for all remaining PFAAs the enhancement exceeded 450 with the exception of the C14 carboxylate (106).
Can changes in leaf water potential be assessed spectrally?
Authors: Elsayed Salah , Mistele Bodo , Schmidhalter Urs
Published: November 2018

Leaf water potential (LWP) is an important indicator of plant water status. However, its determination via classical pressure-chamber measurements is tedious and time-consuming. Moreover, such methods cannot easily account for rapid changes in this parameter arising from changes in environmental conditions. Spectrometric measurements, by contrast, have the potential for fast and non-destructive measurements of plant water status, but are not unproblematic. Spectral characteristics of plants vary across plant development stages and are also influenced by environmental factors. Thus, it remains unclear whether changes in leaf water potential per se can reliably be detected spectrometrically or whether such measurements also reflect autocorrelated changes in the leaf water content (LWC) or the aerial plant biomass. We tested the accuracy of spectrometric measurements in this context under controlled climate chamber conditions in series of six experiments that minimised perturbing influences but allowed for significant changes in the LWP. Short-term exposure of dense stands of plants to increasing or decreasing artificial light intensities in a growth chamber more markedly decreased LWP than LWC in both wheat and maize. Significant relationships (R2-values 0.74–0.92) between LWP and new spectral indices ((R940/R960)/NDVI; R940/R960) were detected with or without significant changes in LWC of both crop species. The exact relationships found, however, were influenced strongly by the date of measurement or water stress induced. Thus, global spectral relationships measuring LWP probably cannot be established across plant development stages. Even so, spectrometric measurements supplemented by a reduced calibration dataset from pressure chamber measurements might still prove to be a fast and accurate method for screening large numbers of diverse lines.
Tissue size and cell number in the olive (Olea europaea) ovary determine tissue growth and partitioning in the fruit
Authors: Rosati Adolfo , Caporali Silvia , Hammami Sofiene B. M. , Moreno-Alías Inmaculada , Paoletti Andrea , Rapoport Hava F.
Published: November 2018

The relationship between tissue size and cell number in the ovary and tissue size in the fruit, was studied in eight olive (Olea europaea L.) cultivars with different fruit and ovary size. All tissues in the ovary increased in size with increasing ovary size. Tissue size in the fruits correlated with tissue size in the ovary for both mesocarp and endocarp, but with different correlations: the mesocarp grew about twice as much per unit of initial volume in the ovary. Tissue size in the fruit also correlated with tissue cell number in the ovary. In this case, a single regression fitted all data pooled for both endocarp and mesocarp, implying that a similar tissue mass was obtained in the fruit per initial cell in the ovary, independent of tissues and cultivars. Tissue relative growth from bloom to harvest (i.e. the ratio between final and initial tissue size) differed among cultivars and tissues, but correlated with tissue cell size at bloom, across cultivars and tissues. These results suggest that in olive, tissue growth and partitioning in the fruit is largely determined by the characteristics of the ovary tissues at bloom, providing important information for plant breeding and crop management.
Ballooning Modes in a Toroidally Rotating Plasma
Authors: Sen S.
Published: November 2018

The stability of ideal ballooning modes in the presence of a rigid
toroidal rotation is revisited. Two stabilising contributions arising due to
rigid toroidal rotation are identified. These stabilising contributions can be
particularly significant for present and future generations of low and
ultra-low aspect ratio tokamaks.
General Coordinatisations of the Flat Space—Time of Constant Proper-acceleration
Authors: Tilbrook David
Published: November 2018

We examine space-times which are described by a metric of the form
ds2 =
V2(X)dT2
- U2
(X)dX2 -
dY2 -
dZ2 in which
V =V
(X) and U =
U(X) are continuous functions of
X only and which admit diffeomorphisms into Minkowski
space-time. It is shown that such space-times are associated with rigidly
accelerating frames of reference by appeal to the notion of a fundamental
observer. The condition for the existence of the diffeomorphism is derived
from first principles and some special cases of coordinates are discussed.
Effects of the Dust Charge Fluctuation and Ion Temperature on Large Amplitude Ion-acoustic Waves in a Dusty Plasma
Authors: Nejoh Y. N.
Published: November 2018

The effects of the dust charge fluctuation and ion temperature on large
amplitude ion-acoustic waves are investigated in a plasma with a finite
population of negatively charged dust particles, by numerical calculation. The
nonlinear structures of ion-acoustic waves are examined, showing that the
conditions for existence sensitively depend on the effects of the variable
charge of dust grains and ion temperature, electrostatic potential and Mach
number. The electrostatic potential on the surface of dust grain particles
increases the dust charge number. The effect of the ion temperature increases
the propagation speed of the ion-acoustic wave, and decreases the dust charge
number. It is found that both compressive and rarefactive solitons can
propagate in this system and the criterion for both solitons depends on the
ion temperature. The region for existence of large amplitude ion-acoustic
waves significantly depends on the dust charging. New findings of large
amplitude ion-acoustic waves with variable charge dust grains and finite ion
temperature in a dusty plasma are predicted.
A New Class of Brans - Dicke Cosmological Models with Causal Viscous Fluid
Authors: Singh G. P. , Ghosh A S. G. , Beesham Aroonkumar
Published: November 2018

The behaviour of solutions to the Brans–Dicke equations of
Friedmann–Robertson–Walker models with bulk viscous fluid source
described by full (i.e. non-truncated) causal nonequilibrium thermodynamics is
investigated. A new class of cosmological solution is obtained for all spatial
sections (k = 0, ± 1).
Glueball Spectrum of SU(3) Lattice Gauge Theory by Plaquette Expansion
Authors: Hollenberg Lloyd C. L. , Wilson M. P.
Published: November 2018

By casting the Hamiltonian of pure SU(3) in 3+1 space–time
dimensions into approximate tri-diagonal form we study the glueball spectrum
of the system. In particular we obtain estimates for the ground state energy
density, the string tension σ, and the masses of the lowest lying
0++ , 1 + - and 2
++ glueballs. These initial calculations lead to
estimates of various mass ratios in general agreement with other studies of
the spectrum.
Ion Confinement in a Toroidal Heliac
Authors: Lewandowski J. L. V.
Published: November 2018

A model to describe an unmagnetised plasma in three-dimensional magnetic
topology is presented. Ion trajectories are integrated numerically and all
finite-Larmor radius effects are retained exactly. A velocity-dependent
collision term is included in the equations of motion. Numerical simulations
relevant to the low-confinement mode of H1-NF are presented and discussed.
Large Amplitude Alfvén Soliton in the Solar Wind and Painlevé Analysis
Authors: Chowdhury A. Roy , Buti B. , Dasgupta B.
Published: November 2018

A detailed analysis of complete integrability is performed for a new set of
equations for large amplitude Alfvén waves in the solar wind recently
derived by Hada. It is observed that there exist two branches of the
Painlevé expansion and the number of resonances is less than the degree
of the equation, thus indicating that the system is not completely integrable.
We have found the exact one soliton solution of the system. This one solution
has the distinctive feature that even the phase part of the complex is a
nonlinear wave packet.
Ab Initio Investigations of the Electronic Structure of HeNH + and HeNH 2+
Authors: Hughes Jason M. , von Ellak I. , Nagy-Felsobuki
Published: November 2018

Electronic structures of HeNH+ and
HeNH2+ were investigated using the all-electron coupled
cluster single, double and triple excitation (CCSD(T)_AE) method
coupled with an augmented correlation-consistent polarised core valence triple
zeta basis set (aug-cc-pCVTZ). For HeNH+ and
HeNH2+, the CCSD(T)_AE/aug-cc-pCVTZ model
yielded cations of Cs symmetry with
2 A″ and 1 A′ ground
electronic states possessing optimised geometrical parameters
{rN-H;
rN-He;
θH-N-He} of {1·064 Å,
1·517 Å, 88·5°} and {1·192 Å,
1·309 Å, 96·2°} respectively. Of all the linear
isomeric forms possible for these two cations, the only converged minimum
energy structures were for the
4Σ- states of
HeHN+ and HeNH+ yielding optimised
structural parameters of {1·093 Å, 2·403 Å,
180·0°} and {1·117 Å, 1·364 Å,
180·0°} respectively. These two linear structures were
calculated to be 9·6 and 18·6 kJ mol-1
respectively above the Cs structure. The calculated
harmonic frequencies were real for all these states and their magnitudes were
sensitive to the incorporation of electron correlation.
Compromising for conservation: a protocol for developing sustainable conservation plansin biologically rich and monetarily impoverished communities.
Authors: Indrawan Mochamad , Garnett Stephen T , Masala Yunus , Wirth Roland
Published: November 2018

TROPICAL rainforests are the most biologically diverse terrestrial habitats on earth yet nearly all such ecosystems are located in developing countries (Ghazoul and Sheil 2010). Responsibility for stewardship of species richness is therefore borne by those who can least afford it. In many areas, poor people have few choices but to make a living by exploiting natural resources in ecologically valuable habitats. Limited education in developing countries can compound the difficulties of trying to develop and enforce conservation practices.

The remote Indonesian Banggai Archipelago, is characterized by high biological diversity and contrastingly low income of its inhabitants. One main obstacle to maintaining the biodiversity is a vicious cycle whereby run-off from shifting agriculture in the
forest deposits silt on coral reefs, putting further pressure on a fish stock already depleted by overfishing and coral reef destruction. This leads to a shortage of animal protein available to the islanders, prompting them to over-hunt forest vertebrates, which are already stressed from habitat destruction.

Biodiversity conservation is complicated by the interplay of many factors outside the realm of biology, societal dynamics, including politics at many levels, decision-makers unschooled in conservation and limited collaboration between scientists
and decision-makers. Therefore conservation practice needs to marry theory with pragmatism, eventually influencing the behavior, values, and decision-making of citizens and politicians alike (Reyers et al. 2010). Local and scientific knowledge can be integrated to provide a more comprehensive understanding of complex and dynamic socio-ecological systems. Only when relevant stakeholders are systematically represented can there be effective participation (Reed 2008).

We investigated linking the conservation of flora and fauna with the livelihoods of the Banggai people, in particular possible trade offs and incentives that may encourage local participation and investment in conservation. This study was conducted
with the ultimate objective of encouraging the creation of locally protected areas and is notable for taking place in one of the most isolated island communities in Indonesia.
The Housing Bomb, Why our addiction to houses is destroying the environment and threatening our society.
Authors: Brueckner Martin
Published: November 2018

THIS book by Nils Peterson and colleagues offers a detailed overview of both the social and environmental consequences of western housing fetishism. Not only do the authors marshal some powerful evidence that attests to the dark side of humanity’s drive towards more and larger homes, they also spell out accessible guidance principles for one-planet housing and point to directions for change across individual, regional, national and international scales. Whilst largely US-centric in orientation The Housing Bomb should resonate strongly across the political North, especially in countries like Australia where US housing patterns
continue to be emulated.
Spin Dynamics in Low-dimensional Magnetic Structures
Authors: Stamps R. L.
Published: November 2018

Maxwell’s equations applied to low-dimensional magnetic structures
result in a number of interesting features. For example, the magnetic fields
generated by two-dimensional arrays of Heisenberg spins can stabilise long
range magnetic order and determine critical temperatures. Aspects of this
problem are discussed, and considerations for the dynamic response of weakly
coupled arrays of fine magnetic particles are presented. Finally, a form of
effective medium theory designed to overcome difficulties in treating
magnetostatic interactions in magnetic nanostructures is described.
Preparation of Motion Entangled Coherent States of Two Cavity Mirrors
Authors: Zheng Shi-Biao
Published: November 2018

A scheme is proposed for the generation of entangled coherent states of two
spatially separated cavity mirrors. In the scheme, a two-level atom is sent
through two cavities, each having a movable mirror, to produce an entangled
photon state for the cavity fields. Then the optomechanical effects further
entangle the mirror motions with the cavity fields. A second two-level atom,
passing through the cavities, is state-selectively measured, which reduces the
mirror motions to an entangled coherent state.We also show how to distinguish
such an entangled state from a classical mixture.
Neutral Currents in the 16O Nucleus
Authors: Mihailescu Dan , Mihailescu Dan , Radu Daniel , Radu Daniel , Dumitrescu Ovidiu
Published: November 2018

The aim of this paper is to investigate the parity and isospin forbidden
á0 decay from 16O
(Jp =
1+; T =
1;Ex = 16.209MeV) to
12C(g.s.) by calculating the longitudinal
AL and the irregular transverse
Ab analysing powers of the
reaction 15N( p,
α0)12C around the 1+,
Ex = 16.2MeV resonance in
16O. The range for the expected interference effect has
been estimated to be AL 3.2
×10-5 and
Ab 2.3 ×
10-5.
A Novel Constraint for the Simplified Description of Dispersion Forces
Authors: Dobson John F. , Dinte Bradley P. , Wang Jun , Gould Tim
Published: November 2018

We propose a novel use of an exact constraint in the construction of simple
approximations for response functions of interacting many-electron systems.
Within its simplest local version, the resulting theory gives improved
approximations for static atomic dipolar polarisabilities without the direct
use of wavefunctions or semi-empirical cutoffs. It leads to correct van der
Waals energies between distant planar systems, but over-corrects existing
cutoff theories for the van der Waals C
6 coefficient for atoms. It is argued that a
nonlocal-response version of the constrained theory will do better.
Electromagnetic and Gravitational Decay of the Higgs Boson
Authors: Delbourgo R. , Liu Dongsheng
Published: November 2018

The decays of a scalar particle, of either parity, into two photons or into
two gravitons are evaluated. The effective interactions are of the form ?
FF , ? FF ~ or ?
RR ,? RR ~ ; in particular,
the Higgs meson decay mode into gravitons is tiny and can be neglected.
Real Critical Current Density and Material Power Law of YBa2Cu3O7-d Epitaxial Thin Film
Authors: Shan Lei , Aruna Sahr Augustine , Xu Xiao-Nong , Wang Zhi-He , Jin Xin
Published: November 2018

The current–voltage characteristics have been measured on
aYBa2Cu3O7-δ
epitaxial thin film. Using a material power law, we determine the temperature
and field dependencies of the characteristic pinning potential
UJand the real critical current
density Jc at different fields and
temperatures. It is shown that Jc
is completely different from the conventional critical current density
JE, which is determined by the
electronic-field criterion. Thus, the time-honoured electronic-field criterion
is no longer reasonable for
high-Tc superconductors. By
further investigation of the results of
Jc and
UJ, we are able to present a
physical picture of the transformation of the pinning potential well with
increasing temperature and hence determine the transition point from
vortex-glass phase to vortex-liquid phase.
Nets Composed of Parts of Circles for the Approximate Solution of Field Problems
Authors: Tasny-Tschiassny L
Published: November 2018

The two� dimensional differential equation

describes the current flow in a sheet of conductivity cr loaded by a transverse current
density , cp being the electrical potential. It is known that equation (1) can be
solved approximately by a procedure in which the two� dimensional continuum is
replaced by a net of straight-line bounded meshes, leading to an electrical network of
conductances. The author shows that meshes bounded by "curvilinear rectangles"
can be equally well dealt with and, on� the basis of different conformal transformation
functimls for the individual meshes, derives the formulae required for a solution, if the
mesh boundaries are circle arcs or circle arcs and straight lines. A good fit of the
contours of the boundaries and equipotentials and their orthogonal trajectories can be
obtained. This reduces the number of meshes without impairing the accuracy. Sharp
corners at boundaries can be dealt with in a similar way. Formulae for a good accuracy
computation of potential gradients and a method for changing th.e mesh size abruptly
are given. Two examples using nets of only four meshes demonstrate the power of
the method, the maximum errors being of the order of a few per cent.
A Method of Correcting the Broadening of X?Ray Line Profiles
Authors: Bracewell RN
Published: November 2018

A numerical method is presented which allows X-ray line profiles Ito be corrected for instrumental broadening. It provides an alternative to the use of Fourier analysis as described by Stokes. A special development of the method (as hitherto used) is necessary to permit its application to X-ray analysis where the Ka doublet constitutes a complication.
Microwave and Metre Wave Radiation from the Positive Column of a Gas Discharge
Authors: Davies LW , Cowcher E
Published: November 2018

Experiments are described in which the intensity of radio-frequency "noise" radiation from the positive column of low pressure discharges in neon was measured at 3000 Mc/s and at 200 Mc/s. Measurements were made by inserting the positive column in a resonant cavity and comparing the cavity output with that from a noise generator of known intensity; corrections were made for contributions to the noise radiation from dissipative elements in the cavity at room temperature. The mean energy of the electrons in the discharge was calculated from measured values of the electric field.
The Characteristics of Tracks in Nuclear Research Emulsions
Authors: Herz AJ , Davis G
Published: November 2018

Formulae are derived giving the dependence of the blob, grain, and gap densities, the total gap length, and the mean gap width in the tracks of charged particles as function of the probability of making a silver halide crystal developable. The growth of the grains during the development process is taken into account. The expressions found are suitable for use in discussions of the effects of changes in emulsion properties, and they show clearly the differences between the various methods of determining the rate of energy loss from the track characteristics. There is good agreement with experiment for both G5 and C2 emulsion.
Radio Emission from Novae and Supernovae
Authors: Mills BY , Little AG , Sheridan KV
Published: November 2018

Attempts have been made to observe the radio emission at 3?5 m from two supernovae and ten novae. Kepler's star was the only reasonably certain identification. A comparison with radio observations of other supernova remnants suggests a constant ratio between the present radio emission and the maximum emission of light. It is concluded that for common novae, which are not detectable as radio sources, this ratio must be smaller than for supernovae. The galactic radio emission near the plane of the Milky Way could be largely the integrated emission of supernova remnants but common novae could not contribute appreciably.
The Masses of the Magellanic Clouds from Radio Observations
Authors: Kerr FJ , de Vaucouleurs G
Published: November 2018

The problem of deriving the masses of the Magellanic Clouds is discussed, and provisional estimates are obtained from 21 cm measurements of the distribution of radial velocity.
Neutron Fluxes Underground
Authors: Mather KB
Published: November 2018

Eugster (1954) reported the neutron flux under 2100 m rock (5880 m water equivalent) to be 26 times that at the ground surface and suggested that radiation was coming from the centre of the Earth. An attempt has been made to confirm this interesting finding by comparing the neutron flux in the Broken Hill mines with that at ground level. Although the counting statistics are rather meagre they should be sufficient to reveal such a marked effect as claimed in the Swiss experiment.
General Method of Exact Solution of the Concentration?Dependent Diffusion Equation
Authors: Philip JR
Published: November 2018

Only three forms of D(6) have previously been known to yield exact solutions of the equation
The Distribution of Ions Formed by Attachment of Electrons Moving in a Steady State of Motion Through a Gas
Authors: Hurst CA , Huxley LGH
Published: November 2018

The distribution of ions formed by attachment of electrons diffusing through a gas is solved exactly, and the results compared with an approximate calculation given earlier by Huxley. The corrections to the approximate results are inside the present experimental error, and so confirm the satisfactory agreement with experiment already obtained.
The Design of Photographic Objectives of the Triplet Family. II. The Initial Design of Compound Triplet Systems
Authors: Cruichshank FD
Published: November 2018

Part II. The general method developed for the type 111 triplet is extended to the initial design of triplet systems having compound components. The possibility of replacing a single lens by an equivalent doublet or triplet allows the single lens to be regarded as not being restricted to values of N and V associated with known glass types. It follows that the glass parameters oc, ~, y, and ~ may be treated as continuously variable over limited ranges. The general effects of the variation of these parameters on the powers and separations of the basic initial solutions are shown in a set of diagrams. As an example, the initial design of a triplet with compound members is given in detail.
The Mobility of Li+ Ions in Helium at 294 K and High E / N Values
Authors: England JP , Elford MT
Published: November 2018

The mobility of Li + ions in helium (294 K) has been measured at E/ N values between 40 and 90 Td using the Tyndall-Powell four-gauze method. The drift distances used varied from 35 to 208 mm. Errors due to 'end effects' were taken into account by extrapolation of the mobility data to large distances. The corrected mobility values are estimated to have an uncertainty of less than 1 %. The present values are compared with previous data and shown to agree to within the experimental error with values calculated from the ab initio interaction potential of Senff and Burton (1986).
Power Balance Models for Rotamak Plasmas
Authors: Donnelly IJ , Rose EK , Cook JL
Published: November 2018

Energy transfer processes are calculated for a range of rotamak plasmas which are modelled by equilibria with plasma pressure proportional to either the poloidal flux function or the square of this function. The latter case is more realistic, so it is used to study the conditions for which global power balance can be obtained for both the electrons and the ions. The absence of a toroidal magnetic field means that there is no neo-classical transport. Provided that the particle and energy diffusion remains classical when the plasma temperature increases, the energy confinement time is predicted to scale as n3/2 R8, where n is the density and R is the radius of the separatrix. As the plasma temperature increases, the dominant energy loss process changes from plasma recycling to electron thermal conductivity and then to ion thermal conductivity.
Interaction Potential of a Charged Particle in a Plane?Sphere Geometry
Authors: Mahanty J , Michalewicz MT
Published: November 2018

The three� dimensional potential of a charged particle tunneling between a flat metal surface and a spherical metal tip is calculated within the framework of the hydrodynamic description of metallic electrons. It is demonstrated that the inclusion of coupling of surface modes in the two electrodes, even for separations as small as 10 times the screening length in either of them, contributes less than 5% of the total potential of a point charge. Hence the potential is obtained as a superposition of contributions from a planar surface and a charge neutral, conducting sphere (and can include a simple classical term for a sphere at a fixed potential). This should enable accurate determination of three� dimensional tunnel currents in scanning tunneling microscope geometry.
Tumbling for Exotic Fermionic Representations in Grand Unified Models
Authors: K Grech Dariusz
Published: November 2018

We consider dynamical symmetry breaking through a tumbling mechanism for exotic representations of fermions in unified models. Possible ways to introduce U(I) gauge symmetry are also discussed. It is shown that the most attractive channel (MAC) hypothesis does not predict physically interesting results unless the peculiar assumption of the maximal preservation of the global SU(3)xU(l) symmetry is made. In such a case the model with two fermionic generations is obtained.
Elevated Duct Effects on Radar Ranges Using an Airborne Microwave Refractometer
Authors: Sarma SBSS
Published: November 2018

Anomalous distribution of humidity and temperature in the troposphere is responsible for significant changes in electromagnetic wave propagation and results in enhancement/degradation of radar ranges, elevation errors etc. The present investigation assesses atmospheric refraction effects in the tropics by producing radar ray traces which depict the path of the airborne radar rays using a three-dimensional ray tracing technique combined with the radio refractivity vertical profile derived using an airborne microwave refractometer. The radar rays at the target can be represented as a sum of normal modes and an assembly of rays reflected from the elevated ducts/layers. The radar range errors at small elevation angles are evaluated.
Predictability of the 12-month Running Averaged Sunspot Number in the Presence of an 8-month Quasi-periodicity on a Solar Cycle
Authors: Pasricha PK , Aggarwal S , Reddy BM , Baskakov V , Kolomitsev OP
Published: November 2018

The method of McNish and Lincoln (1949) for the prediction of the 12-month running averaged sunspot number R12 is supposed to generate useful estimates of R12 for periods up to one year ahead. However, it has been noted that for prediction periods beyond about 8 months, the variance of the prediction of R12 (a~12) approaches the variance of the� 'average' solar cycle. Moreover, the variance a~12 for prediction periods greater than about 8 months is also of the order of the variance (a~l) of the observed monthly-mean sunspot data RI. Since the observed sunspot data RI is used to estimate R12, the variance of RI may be used to attach statistical significance to the predictions of R12. Thus, the sunspot number RI2 cannot be usefully predicted more than 8 months ahead, because the variance of the prediction becomes too large (Le. a~12 ~ a~l). However, a quasi-periodicity of about 8 months in RI is observed during the decay phase of solar cycle 21. It is shown in this paper that the variance a~l ought to be doubled in the presence of the 8-month quasi-periodicity of the sunspot cycle. Further, by taking account of this quasi-periodicity, it is possible to make useful predictions of RI2 up to a year (and more) ahead. An application of the RI2 predictions is in forecasting the ionospheric F2 layer critical frequencies a few months ahead.
Integrability of Low Particle-number Models for Solids
Authors: Henry BI
Published: November 2018

We introduce a model Hamiltonian that describes, for different choices of the parameters, simple anharmonic models for a solid. We have applied the Painleve test to identify integrable and non-integrable cases. In the integrable cases the identification has been confirmed by deriving explicit expressions for the additional conserved quantities. The analysis demonstrates the sensitivity of lattice integrability to both the order of the anharmonicity and the nature of the boundary conditions.
Quantum Electrodynamic Processes in Laser Beams Focused by Lenses with f = 1
Authors: Perlman HS , Troup GJ , Hartin AF , Derlet PM
Published: November 2018

It is shown how the enhancement of Compton scattering and allied QED processes in the f 5 1 lens focus of a high-power laser beam can be calculated, notwithstanding the inapplicability of the Volkov solution, by moving from the bound interaction picture to the first Born approximation in the total interaction picture.
Single Atom Experiments and the Test of Quantum Physics
Authors: Walther H
Published: November 2018

In this paper experiments performed with a one-atom maser and with a few ions stored in a Paul trap are reviewed. Special emphasis is placed on experiments for the test of quantum physics.
Optical Interferometry: The Post-Michelson Era
Authors: Hariharan P
Published: November 2018

Michelson's contributions to optical interferometry, over the half century from 1880 to 1930, won him the Nobel Prize and dominated the field to such an extent that, at the end of this period, optical interferometry seemed to be an area in which there was little left to be done. In retrospect, it is now apparent that this pessimistic view was totally unjustified. Significant advances were, in fact, made over the next two decades, but these were merely a prelude to the explosion of activity that was triggered by the development of the laser and progress in related fields such as fibre optics and nonlinear optics. Some of these advances will be reviewed, and some future possibilities will be discussed.
Method for Production of Uniform Thin Films from the Vapour Phase
Authors: N Pain Geoff
Published: November 2018

A general method is described for production of uniform thin films from the vapour phase. A brief review of the prior art reveals that various approaches to this problem, and in particular substrate rotation, fail to achieve uniformity of thickness and composition in such technologies as molecular beam epitaxy (MBE) or chemical vapour deposition (CVD). The new technique, for which patent protection has been obtained, involves establishment of uniform growth conditions in one direction, and translation of the substrate at a constant rate in a direction perpendicular to the first. The effect is to integrate and average any property in the direction of translation, so that every point on the substrate experiences an identical history, ensuring complete uniformity of the deposited film.
Effect of Streaming Electrons on the Propagation of Electromagnetic Waves in a Magnetised Relativistic Plasma
Authors: Paul SN , Chakraborty S , Roy Chowdhury A
Published: November 2018

Expressions for the first- and third-order dispersion relations have been derived for circularly polarised waves in a magnetised relativistic plasma containing electron streams. From the first-order dispersion relations it is seen that the waves are split into three parts, one of which is reflected causing the formation of standing waves in the streaming plasma. From the third-order dispersion relations, the expression for the shifts of wave number has been obtained. It is observed that the streaming of electrons has a significant contribution to the wave-number shift of the electromagnetic waves.
Envelope Function Theory for Direct-gap Semiconductor Superlattices of Arbitrary Grading Profile
Authors: Duff KJ
Published: November 2018

A systematic development is given for the construction, at any energy in the conduction or valence bands, of all of the solutions to the coupled second-order equations describing electron, light hole, and spin-orbit split-off envelope functions, for arbitrary superlattice grading profile of direct gap materials, retaining all coupling parameters. While some solutions achieve a clear physical significance, attention is also given to those functions which, on their own, are of questionable significance. The procedures are easy to use, and are applied to the case of a sawtooth superlattice of composition Gal-xAlxAs.
Drift Velocity and DT/m Ratio for Electrons in a 0.5% Hydrogen?Xenon Mixture at 295 K
Authors: Elford MT , Sasaki S , Ness KF
Published: November 2018

The momentum transfer cross section for electrons in xenon, am, has been studied using electron transport coefficient measurements for a dilute hydrogen-xenon mixture (0�47% H2- 99 �53% Xe). Drift velocity measurements were made using the Bradbury-Nielsen time-of-flight method at E/N values from 0 �12 to 2�50 Td, pressures from 10�3 to 94�0 kPa and a temperature of 295 K (E is the electric field strength and N the gas number density; 1 Td == 10-17 Vcm2). The ratio DT/f.t (where DT is the transverse diffusion coefficient and {� the electron mobility) was measured using a Townsend-Huxley diffusion chamber at E/N values from 0�035 to 1� 70 Td, pressures from 13�4 to 40�3 kPa, and a temperature of 294 K. Three recently published Urn values for xenon have been tested and shown to be incompatible with both the present drift velocity and DT / f.t measurements.