bluuebunny/crossref_metadata_2025 huggingface dataset:
AC magnetic response of superconducting YBa2Cu3O7/PrBa2Cu3O7 superlattices
Authors: Miu L. , Ivan I. , Ionescu A. M. , Miu D.
Published: July 2016

Vortex activation energy UAC in the critical-state related AC magnetic response of superconductors (appearing in the vicinity of the DC irreversibility line) takes large values, as often reported, which is not yet understood. This behavior is essentially different from that of the vortex-creep activation energy at long relaxation time scales, and may become important for AC applications of superconductors. To elucidate this aspect, we investigated the AC signal of almost decoupled [Y Ba2Cu3O7]n/[PrBa2Cu3O7]4 superlattices (with n = 11 or 4 units cells) in perpendicular DC and AC magnetic fields. In these model samples, the length of the hopping vortex segment is fixed by the thickness of superconducting layers and vortices are disentangled, at least at low DC fields. It is shown that the high UAC values result from the large contribution of the pinning enhanced viscous drag in the conditions of thermally activated, non-diffusive vortex motion at short time scales, where the influence of thermally induced vortex fluctuations on pinning is weak.
First-principle study of hydrogenation on monolayer MoS2
Authors: Xu Yong , Li Yin , Chen Xi , Zhang Chunfang , Zhang Ru , Lu Pengfei
Published: July 2016

The structural and electronic properties of hydrogenation on 1H-MoS2 and 1T-MoS2 have been systematically explored by using density functional theory (DFT) calculations. Our calculated results indicate an energetically favorable chemical interaction between H and MoS2 monolayer for H adsorption when increasing concentration of H atoms. For 1H-MoS2, single H atom adsorption creates midgap approaching the fermi level which increases the n-type carrier concentration effectively. As a consequence, its electrical conductivity is expected to increase significantly. For 1T-MoS2, H atoms adsorption can lead to the opening of a direct gap of 0.13eV compared to the metallic pristine 1T-MoS2.
Ocean pressure sensors characterize a slow-slip earthquake
Authors: Miller Johanna L.
Published: July 2016

The gauges provide the first detailed measurement of centimeter-scale deformation of the seafloor.
Physics, fracking, fuel, and the future
Authors: Marder Michael , Patzek Tadeusz , Tinker Scott W.
Published: July 2016

To contend with the challenges of fueling modern society, the physics community must collaborate with other disciplines and remain broadly engaged in research and education on energy.
Nutritional Factors Involved in Wool Production by Merino Sheep I. The Influence of Fodder Intake on the Rate of Wool Growth
Authors: R Marston Hedley
Published: July 2016

The rate of wool growth (weight of wool produced per unit time), determined in seven sheep subjected to four levels of food intake, ncreased 400-600 per cent. from the lowest to the highest level of feeding and this change was reflected in both the mean length and in the mean diameter of the fibres, the relationship between these variables being characteristic of the individual sheep. The fibre diameter distribut!ons were also affected, the individual fibres responding up to the limit of their capacities in proportion to their cross-sectional areas.
On The Relative Importance of Aerobic Metabolism in Small Nematode Parasites of the Alimentary Tract II. the Utilization of Oxygen at Low Partial Pressures by Small Nematode Parasites of the Alimentary Tract
Authors: Rogers WP
Published: July 2016

Nippostrongylus muris, Haemonchus contortus, Nematodirus spathiger, and N. filicollis are all capable of utilizing oxygen for respiratory purposes even when it is present at very low oxygen tensions. Thus with a partial pressure as low as 5 mm. of mercury the respiration of Nippostrongylus muris may reach 40 per cent. of its maximum rate, whereas Nematodirus spp. and H. contortus may respire at 25 and 12 per cent. of their maximum rates respectively. Further, the results indicate that in vivo the oxygen consumption rates may sometimes reach 80 per cent. of the maximum in vitro rate in the case of Nippostrongylus muris in the small intestine of the rat and 40 per cent. in the case of Nematodirus spp. in the small intestine of the sheep. Haemonchus contortus in the sheep abomasums probably respires at a relatively lower rate than either of the intestinal parasites in vivo.
Electron Microscopic Studies of Spermatozoa I. The Morphology of the Spermatozoon of the Common Domestic Fowl (Gallus Domesticus)
Authors: Grigg GW , Hodge AJ
Published: July 2016

The morphology of the fowl spermatozoon, as revealed by use of the electron microscope and such techniques as partittl enzymic digestion and disruption with distilled water, is described in detail, and compared with that observable by light microscopy.
Electron Microscopic Studies of Spermatozoa II. the Morphology of the Human Spermatozoon
Authors: Hodge AJ
Published: July 2016

Suitable washing techniques, which do not appreciably affect sperm motility, and enzymic digestion, have made it possible to give a clear picture of the finer structures in the human spermatozoon, using the electron microscope.
The Transmission of Witches' Broom Virus Disease of Lucerne by the Common Brown Leafhopper, Orosius ARGENTATUS ( EVANS)
Authors: Helson GAH
Published: July 2016

The disease was transmitted by Orosius argentatus (Evans) collected in infected lucerne crops, and also by groups of virus-free individuals reared under experimental conditions, after having been fed on plants infected with witches' broom virus.
A Study of Some Aspects of The Feeding of the Jassid Orosius
Authors: Day MF , McKinnon Anne
Published: July 2016

The jassid Orosius ingested radiophosphorus when this isotope was incorporated into a plant. The insect excreted approximately 65 per cent. of the ingested 32p within SO minutes after feeding had begun. The amount ingested plus the amount excreted increased linearly with time for the duration of the experiments (up to S days).
The Mechanism of Secretion by the Salivary Gland of the Cockroach Periplaneta Americana (L.)
Authors: Day MF
Published: July 2016

The two main cell types of the cockroach salivary gland, the ductule-containing cells and the zymogenic cells, are together responsible for the secretion of a powerful amylase and a mucoid substance. The evidence presented suggests that the precursors of both these materials are elaborated in the zymogenic cells and are passed to the ductule-containing cells for excretion. The morphology of the secretory ducts suggests that they also play a part in the elaboration of the saliva.
The Occurrence of Barium and Strontium in Insects
Authors: Waterhouse DF
Published: July 2016

Barium and strontium may be detected histochemically by the formation of reddish compounds following the treatment of tissues with sodium rhodizonate. Calcium does not appear to react under the neutral conditions employed in the test. Treatment with chromate inhibits the reaction with barium, but not with strontium, providing a means for distinguishing between these elements. Permanent histological sections can bc produced in the usual manner, so long as a neutral fixative is employed.
Studies in the Metabolism of Plant Cells IX . The Effects of 2,4-Dlnitrophenolon Salt Accumulation and Salt Respiration
Authors: Robertson RN , J Wilkins Marjorie , Weeks DC
Published: July 2016

2,4-Dinitrophenol, while increasing the respiration, inhibits the accumulation of ions by carrot cells. Further investigation is necessary to determine whether the inhibition is due to a direct effect of the dinitrophenol on the mechanism or whether the dinitrophenol indirectly prevents the mechanism from operating by causing some disorganization within the cell, possibly in the mitochondria.
Factors Influencing the Fungistatic Action of 8-Hydroxyquinoline (Oxine) and Its Metal Complexes
Authors: I Anderson Beverley , Swaby RJ
Published: July 2016

The fungistatic effect of oxine against AspergiUus niger is greatly reduced if the medium is first freed of cupric Cu, and toxicity increases with increasing amounts of Cu. The toxicity is overcome by lowering the pH of the medium even in the presence of quite large amounts of Cu.
Ruminal Flora Studies in the Sheep III. The Influence of Different Sources of Nitrogen Upon Nitrogen Retention and Upon the Total Number of Free Microorganisms in the Rumen
Authors: Williams VJ , Moir RJ
Published: July 2016

The data are presented from a replicated feeding trial designed to determine the influence of different sources of nitrogen, fed at a constant level, upon the nitrogen balances and numbers and types of ruminal microorganisms in growing Iambs. Six Merino Iambs were fed a basal ration of oaten chaff and wheaten grain supplemented with six sources of nitrogen: linseed meal, subterranean clover seed, whole powdered egg, casein, urea, and urea plus methionine.
Influence of Oxygen Concentration on the Reduction of Nitrate by a Pseudomonas SP. in the Growing Culture
Authors: Skerman VBD , Lack Jean , Millis Nancy
Published: July 2016

A method is described whereby oxygen tension in growing cultures of microorganisms may be assessed with reasonable accuracy at any time by means of a recording polarograph.
Carbonic Anhydrase Activity in Plants in Relation to Zinc Content
Authors: Wood JG , M Sibly Pamela
Published: July 2016

Throughout the life cycle of oat plants carbonic anhydrase activity, which is restricted to the non-chloroplast fraction of leaves, reaches a maximum value and then decreases. After appearance of deficiency symptoms carbonic anhydrase activity is less in zinc-deficient plants than in fully manured controls of the same age and is associated with a lower zinc content of the leaves.
Wound Healing in the Gut of the Cockroach Periplaneta
Authors: Day MF
Published: July 2016

Incisions in the fore-, rnid-, or hindgut of the cockroach Periplaneta heal in a large percentage of operations. The processes of healing are described. They involve firstly the fonnation of wound tissue from haemocytes, and later the participation of the epithelium. Operations performed on nymphs do not appear to hinder moulting, but the wounds are usually still conspicuous in the resulting adults, except in operations on the midgut, in which healing may be complete. Comparisons are made between the processes of wound healing, neoplasms, and the normal changes of the epithelium at moulting.
On the rate of completion of Diapause Development At Constant Temperatures in the Eggs of Gryllulus Commodus Walker
Authors: Browning TO
Published: July 2016

The median duration of low-temperature treatment required by the eggs of G. commodus in order that they may develop and hatch without interruption due to diapause was least at 12.7�C., slightly longer or about the same at 15.9�C., and considerably longer at 1O.3�C. At S.5�C. it was not found possible to obtain 50 per cent. of the eggs free from diapause.
The Development of Pronuclei in the Rat Egg, With Particular Reference to Quantitative Relations
Authors: Austin CR
Published: July 2016

The development of pronuclei has been studied by exammmg rat eggs freshly recovered at various times between ovulation and the first segmentation.
The Fine Structure and Biosynthesis of Silk Fibroin
Authors: Mercer EH
Published: July 2016

Electron microscopic examination of fibrillar fragments produced by the enzymic disintegration of silk fibroin suggests the existence of fine microfibrils about 100 A in diameter extended parallel to the length of the fibre axis. The microfibrils are similar in width to the crystalline micelles deduced from X-ray diffraction.
Studies on the Digestion of Wool by Insects VII. Some Features of Digestion in Three Species of Dermestid Larvae and a Comparison with Tineola Larvae
Authors: Waterhouse DF
Published: July 2016

Three species of dermestid larvae (Anthrenocerus australis, Anthrenus verbasci, and Attagenus piceus) are shown to be capable of digesting wool.
Properties of the Membranes of Rat and Rabbit Eggs
Authors: Braden AWH
Published: July 2016

The properties of the membranes of rat and rabbit eggs-the zona pellucida, cumulus oophorus, and in the rabbit, the so-called "albumen" layerhave been studied. By histochemical techniques, it has been shown that all the membranes contain a large proportion of polysaccharide. The zonas are shown to be neutral or weakly acidic mucoproteins, being less acidic than the matrix of the cumulus oophorus, which is composed of hyaluronic acid and protein. Protein is demonstrable histochemically only in the zonas, but ready dissolution of the "albumen" layer and the matrix of the cumulus by pure proteinases indicates that protein forms an integral part of the structure of these layers. The term "albumen" is inappropriate, as the layer so designated has the properties of a strongly acidic mucoprotein.
The Resistance of Twelve Varieties of Triticum Vulgare to Erysiphe Graminis Tritici
Authors: Pugsley AT , Carter MV
Published: July 2016

A genetic study has been made af the resistance af 12 varieties af Triticum vulgare ViII. to' a Sauth Australian isalate af Erysiphe graminis tritici. This callectian has been resalved intO' twa pathagenic campanents which may be differentiated by their reactians an the variety ChuI.
Tissue Tensions in Bryophyllum Calycinum Salisbury
Authors: Baas Becking LGM , Everson RG
Published: July 2016

Turgor changes following the isolation of various tissue systems from internodes of Bryophyllum calycinum Salisbury plants have been examined and related to the new environmental conditions. The structural changes in cambium-phloem parenchyma strips have been analysed.
Enzymes of Aspergillus Oryzae III. The Sequence of Appearance and Some Properties of the Enzymes Liberated During Growth
Authors: Crewther WG , Lennox FG
Published: July 2016

When a strain of the mould Aspergillus oryzae is grown in surface culture on a protein-free sucrose-tartrate medium, enzymes are released into the culture medium in the following order: first, the carbohydrases sucrase and amylase together with phosphatase, second, the proteases and esterases, and third, catalase. Their liberation is accompanied by the appearance of protein nitrogen in the medium and loss in weight of the mycelium.
The Effect of Borate on the Oxygen Uptake of Brain Tissue in Krebs Phosphate Ringer Solution
Authors: Trautner EM , Messer M
Published: July 2016

The effect of borate on the respiration of guinea pig brain cells in Krebs phosphate Ringer solution in the absence of any added substrate and in the presence of glucose and fructose has been investigated.
The Photochemical Inactivation of Indoleacetic Acid Sensitized by Non-Protein Components of Plant Tissues
Authors: Goldacre PL
Published: July 2016

A study has been made of the IAA-destroying activity of the brei of etiolated pea epicotyls other than that due to the enzyme IAA oxidase. The protein-free dialysate sensitizes the destruction of IAA in the light but not in the dark. Blueviolet light is most effective, followed by blue-green, green, red, and yellow.
Physiological Studies on Thrips in Relation to Transmission of Tomato Spotted Wilt Virus
Authors: Day MF , Irzykiewicz H
Published: July 2016

The hydrogen ion concentration of the midguts of larval and adult Thrips tabaci and T. imaginis is between pH 5�0 and 5�6. The oxidation-reduction potential at these values is between + 0�184 and + 0�262 V. There is thus no difference between thrips that are vectors and those that are not vectors of the virus causing tomato spotted wilt. Furthermore, the pH and Eh conditions in the midgut of larval T. tabaci are unsuitable for long survival of the virus.
The Blood Sources of Some Australian Mosquitoes
Authors: Lee DJ , Clinton KJ , O'gower AK
Published: July 2016

The results of over 1400 precipitin tests on the stomach contents of engorged mosquitoes to determine the source of their blood meals are recorded. Fifteen species of mosquitoes are included in this survey, but three .species, Anopheles annulipes, Culex fatigans, and C. annulirostris, dominated the collections.
The Elastic Anisotropy of Keratinous Solids I. The Dilatational Elastic Constants
Authors: RacheI  Makinson K
Published: July 2016

The elastic anisotropy of four forms of a-keratin, ram's horn, rhinoceros horn, baleen (whalebone), and the cortex of African porcupine quill, has been studied by measurement of the velocity of propagation of dilatational elastic waves of 5 Mc/s frequency along the principal axes, by the total reflection method. It has been found that ram's horn is transversely isotropic about the radial direction and that rhinoceros horn is approximately transversely isotropic about the fibre direction. This is directly correlated with the histological structure of these materials, which here predominates over the molecular structure in determining the nature of the elastic anisotropy.
The Use of Regressions to Increase Heritability
Authors: Rendel JM
Published: July 2016

The difficulties of applying correction factors to eliminate non-genetic variance in selective breeding work are discussed. The use of a second character as an index of environmental change is explored and related to the general formula for selection indices. Tibia length and body weight in mice are used to demonstrate points made in the theoretical discussions of the first part of the paper.
The Role of Molybdenum in Nitrate Reduction Inhigher Plants
Authors: Spencer D , Wood JG
Published: July 2016

Experiments are described which were designed to locate the molybdenumrequiring step in the chain of reactions involved in nitrate utilization in higher plants.
Regeneration and the Moulting Cycle in. Blattella Germanica L. III. Successive Regeneration of Both Metathoracic Legs
Authors: O'farrell AF , Stock A
Published: July 2016

At 29�C, 70 per cent. relative humidity, removal of the left and right metathoracic legs in succession, at intervals of 1, 2, or 3 days, in first instar Blattella germanica of known age~, results in the appearance at the first moult of:
Enzymic Activity of Particles Isolated from Various Tissues of the Pea Plant
Authors: Smillie RM
Published: July 2016

A method is described for the preparation from green and etiolated tissues of the pea plant, of cytoplasmic particles 'with high oxidative activities in the presence of intermediates of the tricarboxylic acid cycle. The cofactor requirements have been investigated, and for preparations from etiolated pea stems, a phosphorylative ability comparable with animal mitochondria has been obtained. With certain of these preparations an oxidation of butyrate has been demonstrated.
Nutrient Interactions and Deficiency Diagnosis in the Lettuce
Authors: Goodall DW , Grant Lipp AE , Slater WG
Published: July 2016

A sand-culture experiment with lettuces is described, having as its principal purpose the study of the relationship between the potential responses of plants to applications of nitrogen, phosphorus, and potassium fertilizers and the composition of. their foliage. Plants were supplied initially with five levels of these nutrients in all combinations, samples of plant material were taken fot analysis at various stages of development, and at 44 days from sowing additional quantities of nutrients were supplied to some of the cultures in order that their response potentialities might be determined. The present paper analyses the effects of the nutrient interactions on plant dry weight, further results being left to subsequent papers.
Microelectrode Experiments on Nitella
Authors: Walker NA
Published: July 2016

Tubular glass micro electrodes containing concentrated KCl solutions have been inserted into internodal cells of Nitella, under adequate visual control, and the electric potentials of cytoplasm and vacuole measured. The potential of the cytoplasm is found to be close to that of the sap. For one of the groups of cells studied, this potential was - 160 m V referred to the solution bathing the cell when this was O� 0001N KC!. Changes in the KCI concentration of this solution caused the potential of the cytoplasm to change in a similar way to that of the sap.
The Water Relations of Growth and Respiration of Salmonella Oranienburg At 30°C
Authors: Christian JHB
Published: July 2016

The influence of water activity (aw ) on growth, respiration, and Na and K content of cells during respiration has been studied for Salmonella oranienburg. Sucrose, glucose, glycerol, NaCI, and KCI were added to control aw' The organism grew in a glucose-inorganic salts medium at 0�97 a", when any of these solutes was used to adjust a,v, but at 0�96 aw only when glycerol was employed. Respiration was not inhibited in glycerol-adjusted solutions at am's at which the rate was very low in other solutes. When a", was controlled by sucrose or glucose, cells oxidizing glucose accumulated K but not Na. Accumulation of K was greatest at 0�975 aw In solutions of NaCI, accumulation of K was small and in glycerol solutions it was absent. The differences between glycerol and the other solutes tested are discussed.
Studies on Chitin
Authors: Hackman RH
Published: July 2016

The effects of pH, salt concentration, and temperature on the adsorption of a water-soluble insect cuticular protein to chitin have been investigated. The adsorption is dependent upon pH, decreasing rapidly as the pH increases from the region of the isoelectric point of the protein. Increase in salt concentration decreases adsorption but the adsorption appears to be little influenced by changes in temperature. Tyrosine-rich protein fractions are preferentially adsorbed. The adsorption is partly irreversible and an increase to pH 9 is necessary before all the adsorbed protein can be removed. It is concluded that there is only a weak bonding between the chitin and the water-soluble cuticular protein.
Concept of General and Specific Combining Ability in Relation to Diallel Crossing Systems
Authors: Griffing B
Published: July 2016

A detailed examination of the concept of combining ability in relation to diallel crossing systems is made. Eight different analyses aro presented. 'l'hese result from a consideration of four different diallel crossing systems together wit.h two alternative assumptions with regard to the sampling nature of tho experimental material. A numerical example is given.
The Inhibition of Photosynthesis by Oxygen I. Compa. Rative Physiology of the Effect
Authors: Turner JS , Todd Mary , Brittain EG
Published: July 2016

(i) A comparative summary is presented of new and published data on the inhibition of photosynthesis by high oxygen concentration.
Inhibition of Transport of Indole-3-Acetic Acid in the Etiolated Hypocotyl of Phaseolus Vulgaris L.
Authors: Zwar JA , Rijven AHGC
Published: July 2016

The effect of a number of auxins and auxin analogues on the basipetal transport of illdole-3-aeotie acid (IAA) in 5-mm segments of hypocotyls of i)-day-old etiolated Phaseolus vulgari8 L. seedlings has been investigated.
The Influence of the Thyroid on Wool Follicle Development in the Lamb
Authors: Ferguson KA , Schinckel PG , Carter HB , Clarke WH
Published: July 2016

Thyroidectomy of the newborn lamb prevents the maturation of secondary wool follicles. The administration of l-thyroxine to thyroidectomized lambs allows normal follicle development.
Electric Oscillations Generated by Plant Roots and a Possible Feedback Mechanism Responsible for Them
Authors: Scott BIH
Published: July 2016

An account is given of rhythmic variations which have been observed in the electric field generated by bean roots growing in water. These electric oscillations which have periods of about 5 min have been studied using apparatus which records automatically at frequent intervals the potential pattern near the root. A description is given of this apparatus and of a very sensitive instrument for recording the rate of elongation of the root.
Wound Healing of the Potato Tuber in Relation to Infection by Phytophthora Infestans (Mont.) De Bary
Authors: Müller KO
Published: July 2016

The protective action of healing potato tuber tissue against Phytophthora infestans (Mont.) De Bary is made manifest in two ways:
Physiology of Pea Fruits III. Changes in Starch and-Starch Phosphorylase in the Developing Seed
Authors: H Turner Donflla , Turner JF
Published: July 2016

During the growth of pea seeds there is a period in which the starch content rises rapidly and the sucrose content falls. This paper describes a study of the control of this starch synthesis. A method was developed for the assay of starch phosphorylase in peas and the changes in enzyme activity during development of the pea seed were followed. Over most of the period of development a linear relationship existed between the rate of starch synthesis and starch phosphorylase activity. It is suggested that the activity of starch phosphorylase may be a major factor in controlling the rate of starch formation in the pea. The rate of starch synthesis began to decrease when the pea ceased to gain water and the linear relationship then no longer held. The bearing of these observations on sugar--starch relationships and on the general problems of growth is discussed.
The Influence of Progressive Increases in total Soil Moisture Stress on Transpiration, Growth, and Internal Water Relationships of Plants
Authors: Slatyer RO
Published: July 2016

The responses of tomato (Lycopersicon esculentum (Mill.), privet (Ligustrum lucidum Ait.), and cotton (Gossypium barbadense L.) to conditions of increasing total soil moisture stress were measured in terms of vegetative growth, stem elongation, transpiration, leaf turgor, diffusion pressure deficit, and osmotic pressure.
The Effect of 3-Indolylacetic Acid on the Binding of Pectin Methylesterase to the Cell Walls of Tobacco Pith
Authors: Glasziou KT
Published: July 2016

3-Indolylacetic acid (IAA) was found to promote the binding of pectin methylesterase (PME) to a cell wall fraction prepared from tobacco pith, the effect being increased by increasing concentration of IAA to a peak of activity, after which inhibition occurred.
The Amino Acid Composition of hydrolysates of Microbial Preparations From the Rumen of Sheep
Authors: Weller RA
Published: July 2016

Samples of bacteria and of protozoa were separated from the rumen fluids of sheep which had been fed four different types of ration. Amino acid analyses by ion-exchange chromatography were performed on hydrolysates of "whole protein" preparations of the microbial fractions.
Physiology of Pea Fruits IV. Changes in Sugars in the Developing Seed
Authors: Turner JF , H Turner Donella , Lee JB
Published: July 2016

Paper chromatographic methods were developed for the estimation of sugars in plant tissues and were used to follow changes in some individual sugars during the development of the pea seed. Sucrose was the predominant sugar present in the seeds and there were smaller quantities of fructose, glucose, and galactose. The amounts of fructose and glucose were approximately equal at all stages of develop. ment. The sucrose, fructose, and glucose contents of the seed increased in the early stages of development but decreased during the phase of rapid starch synthesis. The galactose content increased to a maximum at a later state than the other sugars estimated. The concentrations of sucrose, fructose, and glucose in the seeds were compared with the concentrations in the leaves, stems, and hulls. The possible significance of the changes in sugars in relation to the metabolism of the pea seed is discussed.
The Lag Period in Auxin-Induced Expansion of Storage Tissue and Coleoptiles
Authors: Adamson Heather , Adamson D
Published: July 2016

Auxin caused a rapid shift in the point of incipient plasmolysis of a number: of tissues which showed auxin-induced expansion. The plasmolysis shift was not caused by dilution of the cell sap and might be due to an effect of auxin on the adhesion between cytoplasm and cell wall.
Simulation of Genetic Systems by Automatic Digital Computers II. Effects of Linkage on Rates of Advance Under Selection
Authors: Fraser AS
Published: July 2016

Rates of progress of single populations under selection pressure have been simulated by an automatic electronic computer. Varying intensities of selection and tightness of linkage are compared, showing that linkage produces no qualitative effect on the rates of advance at values greater than 0�005, i.e. 0�5 per cent. recombination.
The Effect of Auxins on the Binding of Pectin Methylesterase to Cell Walls
Authors: Glasziou KT , D Inglis Sue
Published: July 2016

Further studies on the binding of pectin methylesterase (PME) to cell wall preparations are described. The PME of extracts of wall preparations from artichoke tubers was separated into three fractions, A, B, and O. Two similar fractions (A and 0) were obtained from tobacco pith wall preparations. The amount of fraction A type PME which could be adsorbed to wall preparations was increased by the addition of 2,4.dichlorophenoxyacetic acid (2,4.D), but not by calcium ions. Neither 2,4.D nor calcium increased the adsorption of fraction B, but calcium and not 2,4�D increased the amount of fraction 0 adsorbed to the wall preparations.
Restriction of Infection Threads in Nodulation of Clover and Lucerne
Authors: F Purchase Hilary
Published: July 2016

Clover and lucerne roots from plants grown in tube culture were examined for infection thread formation and nodule number. The number of infection threads was about equal to the number of nodules in Trifolium pratense L.; this relation was shown to hold for abundantly and sparsely nodulating plants and for bacterial inocula.nts producing large and small numbers of nodules.
Environment and Sporulation in Phytopathogenic Fungi I. Moisture in Relation to the Production and Disoharge of Conidia of Peronospora Tabaoina Adam
Authors: Cruickshank IAM
Published: July 2016

In an investigation into the effects of water relations on sporulation of Peronospora tabacina Adam in tobacco leaf disks the following results were obtained:
The Inheritance and Ecological Significance of Seed Dormancy in Subterranean Clover (Trifolium Subterraneum l.)
Authors: Morley FHW
Published: July 2016

Seed dormanoy in subterranean clover ('1'rifolium 8ubterraneum L.) was shown to be dependent, at least in part, on the gen'otype of the embryo, as distinot from that of the testa. Analyses of data from F ;s, and from a diallel, demonstrated that degree of dormanoy was highly heritable. The average results of seeds from F 1 plants were similar to those from the mid-parent. But results from four sets of F. plants indioated a tendenoy for dominance of high dormancy.
The Inhibition of Photosynthesis by Oxygen II. The Effect of Oxygen on Glyceraldehyde Phosphate Dehydrogenase From Chloroplasts
Authors: Turner JS , Turner JF , Shortman KD , E King Judith
Published: July 2016

(i) An extract containing glyceraldehyde phosphate dehydrogenases was prepared from the chloroplasts of silver beet. Diphosphopyridine nucleotide (DPN) and triphosphopyridine nucleotide (TPN) functioned as cofactorS for the enzyme activity.
Studies in Anaphylaxis IV. The Effects of Adjuvants and of Haemophilus Pertussis on the Antigenic Properties of Bovine Plasma Albumin in the Mouse
Authors: Sobey WR , Adams KM , Short BF
Published: July 2016

An optimal shocking dose of 0�05 mg for bovine plasma albumin was found over a wide range of alum-precipitated sensitizing doses.
Physiology of Cereal Grain II. Starch Granule Formation in the Developing Barley Kernel
Authors: May LH , Buttrose MS
Published: July 2016

Types, numbers, volumes, and weights of starch granules in the barley endosperm were measured at different times from anthesis to maturity. The formation of two types of granule was confirmed: the first (type A) was initiated until 15 days after anthesis; the second (type B) between 18 and 30 days. At maturity there were approximately 10 times as many type B granules as type A, although the latter made up 90 per cent. of the total granule volume. There was a linear relationship between starch granule and endosperm volume throughout kernel development, while the rate of increase in volume per unit granule volume was the same, irrespective of granule size, at anyone time. Starch weight increased as endosperm dry weight increased although the precise form of this relationship is in doubt. The interrelationships between starch granule weight and volume, and also endosperm dry weight and volume, suggest that both starch granules and endosperm increase in density during development.
The Influence of the Soil Moisture Regain on the Expulsion of the Larval Mass of the Nematode Anguina Agrostis From Galls.
Authors: Collis-George N , Blake CD
Published: July 2016

The morphology of galls forrned on Agrostis tenuis Sibth. following invasion of the floret by the nematode Anguina agrostis (Steinbuch) Filipjev is considered, and a mechanism proposed for expulsion of the mass of second-stage larvae contained within these galls.
The Digestion of Wool by a Keratinolytic Bacillus
Authors: Molyneux GS
Published: July 2016

The occurrence, isolation, and characteristics of an aerobic, mesophilic, spore-forming bacillus capable of separating wool and hair into their constituent cuticular and cortical cells are described.
Differential Specificity Exhibited by Two Germination Inhibitors Present in Echium Plantogineum L.
Authors: Ballard LAT , Grant Lipp AE
Published: July 2016

The widespread occurrence of seed-germination inhibitors which come from sources external to seeds, and which apparently control germination by inhibiting embryo growth (mainly the radicle) once it has started (Moewus and Schader 1951; Mayer and Evenari 1952) is well appreciated. Examples of this class of inhibitor have been detected both in the juices or extracts of fruits or other structures derived from parts of flowers (Evenari 1949; Moewus, Moewus, and Schader 1951), and in vegetative structures (Konis 1947; Winter and Sievers 1952; Yardeni and Evenari 1952; Bublitz 1953; Winter and Bublitz 1953). It is also recognized that they are largely non-specific, in that a given inhibitor may react differently against different seeds, as well as a given seed showing different sensitivity to different inhibitors (Evenari 1949; Koller 1955; Toole et al. 1956). It does not appear to have been explicitly stated that both these aspects of non-specificity may be observed in a single source. Evidence to this effect is presented in this communication.
Translocation of Labelled Assimilates in the Soybean
Authors: Thaine R , I Ovenden Stella , Turner JS
Published: July 2016

When 14C02 was supplied to a limited area of a mature illuminated leaf of soybean, the radioactive compounds appeared rapidly in the root, the apex of the shoot, and in young unexpanded leaves. Translocation to these "sinks" took place in the light, during photosynthesis at the source.
Residual Effects of Auxin, Chelating Agents, and Metabolic Inhibitors in Cell Extension
Authors: Carr DJ , Ng EK
Published: July 2016

The growth-promoting action of auxin on wheat coleoptile segments can be separated from the act of cellular expansion by use of the technique of Cleland and Bonner (1956). The effects of a pretreatment with auxin ("residual effects") in hypertonic mannitol are manifested later when the coleoptiles are transferred to water. Auxin action, but not water uptake, requires aerobic conditions.
Studies on Oxidized Wool III. Ion-Exchange and Acid-Uptake Characteristics
Authors: Thompson EOP , O'donnell IJ
Published: July 2016

The acid-uptake and ion-exchange characteristics of wool oxidized with peracetic acid have been re-examined. It has been shown that oxidized wool is capable of ion exchange although the ion-exchange properties are similar to those of carboxylic acid cation-exchange resins and unlike those of sulphonic acid cationexchange resins. Oxidized wool was successfully converted to the ammonium "salt" and the ammonium ions exchanged with barium ions.
Selection for an Invariant·Character, Vibrissa Number, in the House Mouse
Authors: Dun RB , Fraser AS
Published: July 2016

The number of secondary vibrissae in the mouse is normally 19. The tabby gene reduces this to about half and causes a marked variability of vibrissa number. Selection on tabby mice for increase and decrease in vibrissa number has been successful. These selection lines were maintained in segregation for + and Ta alleles, and this selection, practised solely on tabby mice, has resulted in both an increase and decrease in vibrissa number in normal mice.
Variation and Dominance at the Scute Locus in Drosophila Melanogaster
Authors: Rendel JM
Published: July 2016

A genotypic scale, which is additive, has been worked out for variation of scutellar bristle number in D. melamoqaster, sc+ is shown to be partially dominant to scs�, the first substitution of SCSC for sc+ having about six times more effect on genotypic value than the second. Canalization at four bristles is responsible for complete dominance of sc+ in stocks whose mean genotypic value gives a mean phenotype of four bristles in sc+ flies. A function converting the phenotypic to the genotypic scale is given which could be used in heritability analysis.
The Respiratory Chain of Beetroot Mitochondria
Authors: Wiskich JT , Morton RK , Robertson RN
Published: July 2016

Mitochondria were isolated from root tissue of red beetroot (Beta vulgaris L.) and the components of the respiratory chain for oxidation of succinate and of reduced diphosphopyridine nucleotide (DPNH) were studied. Succinate, DPNH, ferrocytochrome c, and malate were used as substrates, and 2,6-dichlorophenolindophenol, ferricytochrome c, and oxygen as hydrogen (electron) acceptors. DPNH was oxidized without addition of cytochrome c and malate without addition of DPN. These observations suggest that the respiratory chain was retained intact in the isolated mitochondria. Cytochromes b, C1. and c were identified spectroscopically by the positions of their characteristic ex-absorption bands. The very small amount of cytochrome c present may indicate some loss of this component during isolation of the mitochondria. An absorption band near 600 mp' was attributed to cytochromes (a+a3).
Some Effects of Boron on Root Growth
Authors: Neales TF
Published: July 2016

The absence of boron in the root environment reduced the total linear growth of the radicles of the four dicotyledon and one monocotyledon species studied. After growth for 4 days in a boron-free medium, the growth rate of the maize radicle was comparable to that in a plus-boron medium, whilst the growth of the field bean radicle ceased. The minimum boron requirement for the unrestricted growth of the field bean (Vicia faba val'. minor) radicle over 120 hI' was 0�005 p.p.m. B. Each microgram of boron in this medium evoked a mean radicle elongation of 51 mm.
Ionic Relations of Cells of Chara Australis III. Vacuolar Fluxes of Sodium
Authors: Hope AB , Walker NA
Published: July 2016

Estimates have been made of the vacuolar influx (<Pi) and efflux (<Po) of sodium in cells of Ohara australis R.Br. var. nobili8 A.Br. from measurements of radioactivity in extracted sap samples or from direct counts of single cells, using the isotope 22Na.
The Metabolism of Phloem Isolated From Grapevine
Authors: Canny MJ , Markus Katalin
Published: July 2016

Small slices of phloem tissue have been isolated from grapevine canes and cultured in sugar-buffer solutions, and measurements made of the respiration rate and of the changes of sugar concentration in the tissue. Calculations from these measurements of the permeability of the tissue to sucrose, and of the rate of sucrose synthesis from glucose and fructose, show that the phloem is not very different from other plant tissue in either activity. The bearing of these findings on our knowledge of the translocation of carbohydrates by the phloem is discussed.
An Investigation of the Polysaccharides Present in Sugar Mill Syrups
Authors: Sutherland GK
Published: July 2016

Two major polysaccharides have been found in syrups obtained from various sources. They were separated by fractional precipitation with ethanol, and the homogeneity of the fractions was checked by moving-boundary electrophoresis. One of the polysaccharides was found in all samples examined and appeared to be a hemicellulose type. The other polysaccharide was a polyglucose of the dextran type, and its appearance was associated with large increases in the viscosity of the syrup. The possible origins of the polysaccharides are discussed.
Theoretical Consequences of Truncation Selection Based on the Individual Phenotype
Authors: Griffing B
Published: July 2016

Theoretical consequences of truncation selection based on the individual phenotype are examined for the following cases of increasing genetic complexity: (i) an arbitrary number of alleles at a single locus, (ii) an arbitrary number of alleles at each of two linked loci, and (iii) a completely general genetic situation.
The Effect of Nutrient Deficiencies on the Hill Reaction of Isolated Chloroplasts From Tomato
Authors: Spencer D , Possingham JV
Published: July 2016

Tomato plants were grown deficient in each known essential macro- and micronutrient (except chlorine) and the effect of each deficiency on the Hill reaction activity of chloroplasts isolated from these plants was studied.
The Electric Resistance of the Cell Membranes in a Chara and a Nitella Species
Authors: Walker NA
Published: July 2016

Experiments with microelectrodes are described which demonstrate that the plasmalemma (outer cytoplasmic membrane) is responsible for most of the direct current resistance in cells of Nitella. Further experiments show that the microelectrode method gives reliable measurements of the membrane resistance in such cells. The resistance of the plasmalemma, in the young N itella cells used, and in various media, ranged from 5 to 50 k.Q em", while the resistance of the tonoplast was less than 3 k.Q em". The combined membrane resistance of the mature Ohara cells used ranged from 10 to 30 k.Q em" with a mean value of 15 k.Q em", the cells being bathed in 1 ruN NaCI solution.
Short Communication Complexes of Copper With Some Pyrrolizidine Alkaloids and With Some of Their Esterifying Acids
Authors: Farrington KJ , Gallagher CH
Published: July 2016

Bull et al. (1956) and Bull and Dick (1959) have shown that the repeated intake of pyrrolizidine alkaloids of the plant Heliotropium europaeum can lead to severe liver damage, and to the abnormal accumulation of copper in the livers of sheep and rats.
Dissemination of Conidia of Peronospora Tabacina Adam
Authors: Hill AV
Published: July 2016

Conidia of P. tabacina in the atmosphere of tobacco plots and glass-houses were trapped by means of a Hirst spore trap.
Studies Concerning the Inheritance of Ascospore Length in Neurospora Crassa I. Studies on Large-Spored Stra,Ins
Authors: Lee BTO , Pateman JA
Published: July 2016

Previous work has shown that the inheritance of ascospore size in certain strains of Neurospora crassa is controlled by a polygenic system with a small cytoplasmic component. Various types of selection lines were set up in strains that had been selected for the large� spored character. The results of these selection procedures are discussed. Experimental work which gives a better estimate of the linkage of part of this polygenic system to the albino locus on chromosome I is reported.
Day-Length Control of Inflorescence Initiation in the Grass Rottboellia Exaltata L.F.
Authors: Evans LT
Published: July 2016

R. exaltata is a strict short�day plant with a critical photoperiod of about 13 hr. The number of short days required for inflorescence initiation varies with age, being 6 with plants 5 weeks old. Exposure to additional short days increases the rate of inflorescence development. The expanding leaf is the one most sensitive to short.day induction and removal of the leaves below it accelerates inflorescence development.
The Inactivity of 1-Docosanol in Some Plant Growth Tests in Relation to the Auxin of Maryland Mammoth tobacco
Authors: Kefford NP
Published: July 2016

In extracts of shoots of Nicotiana tabacum cv. Maryland Mammoth, an auxin was detected with the same chromatographic properties as 3- indolylacetic acid (IAA). This auxin promoted cell extension in Avena coleoptile and first internode sections and was active in the Avena curvature test.
The Isolation and Properties of Some Soluble Proteins from Wool III. The Heterogeneity of the Low-Sulphur Wool Protein Scmka2
Authors: Gillespie JM
Published: July 2016

The low-sulphur wool protein SCMKA2, which gives only single peaks on electrophoresis and ultracentrifugation over a wide range of pH and concentration, has been divided arbitrarily by ammonium sulphate precipitation into two fractions. Amino acid analysis has shown significant differences between the fractions in some amino acid residues, particularly of S-carboxymethyl cysteine, glycine, phenylalanine, tyrosine, and valine.
The Effect of Monomolecular Spreading on the Antigenicity of the Soluble Surface Proteins of Paramecium
Authors: Reisner AH , Macritchie F
Published: July 2016

The highly antigenic soluble surface proteins (serotypic antigens) of Paramecium aurelia are becoming subjects of increasing interest for the study of the genic control of protein synthesis. Sonneborn and Le Suer (1948) demonstrated in a genetically homozygous stock the existence of several distinct serotypes only one of which was detectable at a given time.
Observations on the Structure of Grana-Containing Chloroplasts and a Proposed Model of Chloroplast Structure
Authors: Spencer D , Wildman SG
Published: July 2016

Observations have been made by phase contrast and fluorescence microscopy on chloroplasts both in living cells of higher plants and in an isolated state.
Physiology of Cereal Grain III. Photosynthesis in the Wheat Ear During Grain Development
Authors: Buttrose MS
Published: July 2016

Cereal ears are important as photosynthetic organs in contributing to grain yield and, since ear tissues are the last to yellow, their relative activity may increase during grain development. Glume surface exposed to light has been observed to increase as grains swell, and thus actual photosynthetic capacity of ears may also increase. The contribution of ear photosynthesis to grain growth has now been measured for wheat (Triticum vulgare cv. Gabo) over intervals between anthesis and maturity, by a technique involving stem shading and grain removal.
Water Balance in the Mulgara (Dasycercus Cristicauda), A Carnivorous Desert Marsupial
Authors: Schmidt-Nielsen K , Newsome AE
Published: July 2016

A small Australian marsupial, the mulgara or crest-tailed marsupial-mouse (Dasycercu8 cristicauda Krefft), lives on a predominantly or exclusively carnivorous diet. It, inhabits the most arid part of central Australia where the average rainfall is 5-10 in. per year. In the laboratory and in the absence of heat stress, the animal can maintain or gain weight without drinking water on a diet of whole mice or fresh lean meat. Its kidney can produce a urine highly concentrated with respect to urea, and the large amounts of urea formed on a carnivorous diet can therefore be excreted in a relatively small volume of urine. This desert animal can therefore subsist on the water contained in its food without drinking free water or eating succulent plant material.
The Relation Between the Responses of Wool Growth and Body Weight to Changes in Feed Intake
Authors: Ferguson KA
Published: July 2016

The wool growth responses to changes in feed intake are related to the changes produced in body weight. The relation is expressed by the equation W = Ei-kG, where W = wool growth rate, i = feed intake rate, G = rate of body weight change, and E and k are constants. The ratio of E to k in sheep of different productive efficiency was found to be constant.
N-Acetyl Groups in Wool and Extracted Wool Proteins
Authors: O'donnell IJ , Thompson EOP , Inglis AS
Published: July 2016

N . acetyl groups have been shown to exist in wool and in proteins extracted from wool after reduction with mercaptoethanol followed by alkylation with iodoacetate or after oxidation with performic acid. The evidence suggests that these acetyl groups are located on N-terminal amino groups of peptide chains rather than on the E-amino groups of lysine.