bluuebunny/crossref_metadata_2025 huggingface dataset:
The Chromosomes of Sheep X Goat Hybrids
Authors: Ilbery G Alexander LT , Williams D
Published: July 2016

Hybrid foetuses carried by female goats after mating with male sheep usually die within 2 months of conception (see Alexander, Williams, and Bailey 1967). Since the chromosome number of 54 in the sheep (Makino 1943; Borland 1964; see Plate 1, Fig. 2, for illustration) differs from the 60 in the goat (Makino 1943; Basrur and Coubrough 1964), it is possible that death of these hybrids is due to the development of cell lines with abnormal numbers of chromosomes resulting from mitotic non-disjunction. Berry (1938) could find no evidence of chromosomal nondisjunction in sheep X goat hybrids. However, his display of chromosomes was considerably less clear than those produced by modern methods, and this led to the study by Buttle and Hancock (1966). They reported variations of 53-58 chromosomes per cell in cultures of a minced hybrid embryo, and concluded that it was not possible, on the available evidence, to reject the possibility that death was due to chromosomal non-disjunction; only 5 of 14 cells contained 57 chromosomes. Subsequently, Hancock and Jacobs (1966), using uncultured cells, found fewer departures from the expected number of 57 chromosomes in the hybrid embryos than in the previous study, and fewer departures (10 in 135 cells) in the hybrids, than in sheep and goat embryos (6 in 30 and 6 in 23 cells, respectively).
Effects of Temperature on Growth Characteristics of Bacillus Stearothermophlus
Authors: Bubela B
Published: July 2016

The maximum temperature at which B. 8tearothermophilu8 will grow is considerably decreased if a simple medium free of cofactors is used.
Trans-Aconitate Utilization by Sheep
Authors: Kennady GS
Published: July 2016

Sheep fed diets containing 3�5 and 7� 0% trans�aconitate on a dry weight basis for 5 days appeared normal and maintained normal levels of blood citrate, ketones, and aconitate, but showed large increases in urinary citrate. Calcium and magnesium levels in plasma and urine were not substantially modified. When trans-aconitate was placed in the rumen it disappeared rapidly but did not increase the concentration of rumen volatile fatty acids; blood and urinary aconitate values remained low. trans-Aconitate did not inhibit the fermentation of soluble substrates by rumen microorganisms in vitro. Both cis- and trans-aconitate were fermented slowly.
Studies on Ovalbumin. III. Denaturation of Ovalbumin and S-Ovalbumin
Authors: Smith MB , F Back Joan
Published: July 2016

Ovalbumin and S-ovalbwnin have been compared by measuring their viscosity and optical rotatory dispersion in aqueous formamide solutions at pH 7 and in urea solutions at pH 3�5; also by measuring the optical rotatory dispersion of heated solutions at different salt concentrations, and by a study of ultraviolet differlilnce spectra in alkylamine hydrochloride solutions. The different aggregation behaviour of the two proteins after denaturation suggests a difference in covalent bond structure.
Studies on Ovalbumin. IV. Trypsin Digsestion and the Cystine Peptides of Ovalbumin and S-Ovalbumin
Authors: Smith MB , F Back Joan
Published: July 2016

Conditions for obtaining comparable tryptic digests of denatured, alkylated ovalbumin and S-ovalbumin have been studied. The tryptic peptides soluble at pH 4 -5 were fractionated by gel filtration in 1 % formic acid. The cystine-peptide fraction was resolved into two cystine peptides by chromatography on DEAESephadex, and by amino acid analyses these were shown to be derived from the same region in the molecule. The composition of the cystine peptides from ovalbumin and S-ovalbumin was the same. Further evidence that the disulphide cross-link is in the same position in the two proteins was obtained by comparing partial acid hydrolysates of performic-acid-oxidized cystine peptides isolated from pepsin digests.
An Effect of Kinetin on the Translocation if 14C-Labelled Photosynthate in Citrus
Authors: Kriedemann PE
Published: July 2016

This study indicates that the application of kinetin to a recently formed fruit enhances its ability to import photosynthetic assimilates. Cytokinins are known to influence .the transport of plant metabolites (Letham 1967), and in the case of vine shoots Shindy and Weaver (1967) have recently demonstrated an effect of the kinin 6-(benzylamino)-9-(2-tetrahydropyranyl)-9H-purine on the translocation of 14C_ labelled assimilates. The present paper reports an effect of kinetin (6-furfurylaminopurine) on the accumulation of14C-labelled substrates by citrus fruits (cv. Washington Navel). In such crops the newly formed fruitlet is often unable to compete successfully with adjacent expanding leaves for substrates and this is thought to result in early fruit drop (Haas 1949; Sauer 1954).
Synthesis of Starch in Detached Ears of Wheat
Authors: FJenner C
Published: July 2016

Detached ears of wheat were provided with water or solutions of sucrose and the effects of light and temperature on the synthesis of starch in the grain were investigated. During 24 hr similar amounts of starch are produced in ears cultured on water or sucrose. Thereafter no further synthesis takes place on water, but with solutions of sucrose synthesis continues at a steady rate for several days. Variation in light intensity has no effect on the synthesis of starch in ears supplied with suc� rose. In ears cultured on water or sucrose more starch is made at 30 than at 15� 5�C.
Genetic, Environmental, and Physiological Control of Leaf Orientation in Plantago Lanceolata
Authors: Barber HN , Halsall DM , Palmer JH
Published: July 2016

Considerable diversity in genes controlling leaf orientation in P. lanceolata has been demonstrated in a population growing in the Sydney area. The expression of these genes is greatly influenced by both light intensity and temperature; low light intensity and high temperature induces erect leaf orientation, while conversely high light intensity and low temperature favours the formation of prostrate leaves. Gibberellin apparently blocks the expression of the genes for prostrate leaf orientation. It is suggested that the seasonal variation in air temperature may be the climatic factor chiefly responsible for the disappearance of prostrate leaf orientation in midsummer and for the reappearance of this character in autumn and winter.
Some Photosynthetic Characteristics of Citrus Leaves
Authors: Kriedemann PE
Published: July 2016

Photosynthesis and respiration were measured in the laboratory with an infrared gas analyser using attached leaves of well-established orange and lemon trees growing in pots. Under optimum conditions the photosynthetic activity of mature leaves reached 10-12 mg C02/hr/dm2.
The Influence of the Female Genital Tract on the Metabolism of Rabbit Spermatozoa I. Direct Effect of Tubal and Uterine Fluids, Bicarbonate, and Other Factors
Authors: Murdoch RN , Wite IG
Published: July 2016

The metabolism of glucose and lactate by washed rabbit spermatozoa has been studied in the presence of tubal and uterine fluids, bicarbonate, and other factors.
Comparative Studies of Lipid Metabolism in Zebu and British Cattle in a Tropical Environment. II. Blood Lipid Levels of Cattle on Different Diets
Authors: O'kelly JC
Published: July 2016

Breed differences in plasma lipid levels were previously reported for cattle grazing near Rockhampton, Qld. The present study investigated the blood lipids of British� and Zebu� type cattle subjected to the same dietary treatments. On high-quality diets only plasma non�esterified fatty acid concentrations were significantly affected (P < 0�01) by level of intake. Plasma total cholesterol, phospholipid, and triglyceride levels were depressed by a low-quality diet which elevated the free: total cholesterol ratio.
Developmental Changes in the Late Larva of Calliphora Stygia I. Haemolymph
Authors: F Kinnear Judith , D Martin JA Thomson Marjory , Neufeld GJ
Published: July 2016

Quantitative studies of plasma levels of protein, lipid, and soluble carbohydrate in larvae of O. 8tygia reveal discontinuities at days 6 and 10 of development. From day 3 to 6 plasma levels of protein and lipid increase sharply. After day 6, there is a decline in the concentration of plasma protein which is accelerated. at the onset of pupation. The plasma lipid concentration rises abruptly at day 10, but then declines with the onset of puparium formation. The concentration of soluble carbohydrates in the haemolymph falls slightly between days 6 and 7 of development and commences to rise at about day 10; still higher levels are reached in the quiescent larva and early prepupa.
Proportional Reduction in Shoot Growth of Grapevines With Root Systems Maintained at Constant Relative Volumes By Repeated Pruning
Authors: Buttrose MS , Mullins MG
Published: July 2016

Grapevines were established in water culture and shoot length and leaf number were measured after imposing four levels of root-pruning treatment. These levels (control, and 75, 50, and 25% of the control root volume) were maintained for 8 weeks by making weekly checks followed by appropriate pruning. Shoot dry weights were also measured in some plants at fortnightly intervals.
Gibberellin and Growth in Stone Fruits: Induction of Parthenocarpy in Plum
Authors: I Jackson D
Published: July 2016

Gibberellic acid and a mixture of gibberellin A4 and gibberellin A7 each induced seedless fruit development in plum. Parthenocarpic fruits grew more rapidly early in the season but their final diameters were only 60% of control. Hormones applied only to developing vegetative shoots and not to neighbouring flowers did not induce parthenocarpy. The role of hormones in fruit growth is discussed.
Sex and Selection for a Quantitative Character in Drosophila II. The Sex Dimorphism
Authors: Frankham R
Published: July 2016

Studies were made of the genetics of sex dimorphism for abdominal bristle number
Purification of Potato Virus X and Preparation of Infectious Ribonucleic Acid by Degradation With Lithium Chloride
Authors: Francki RIB , Mclean GD
Published: July 2016

Potato virus X (PVX) was one of the first plant viruses to be partially purified (Bawden and Pirie 1938). Purification by precipitation with salt solutions, however, resulted in aggregation of the particles. which became entwined to form extensive rope and netlike structures (Kleczkowski and Nixon 1950). Markham (1959) suggested that the problem of aggregation and the formation of gels when the virus is treated with salt solutions has prevented PYX from being extensively studied
A Comparison of the Effects of Metabolic Inhibitors on Chloride Uptake and Photosynthesis In Chara Oorallina
Authors: Smith FA , West KR
Published: July 2016

A comparative study has been made of the effects of four metabolic inhibitors on chloride uptake and photosynthetic 14C02 fixation by cells of O. corallina, and on oxygen evolution by chloropl<1sts isolated from the cells. Low concentrations of phlorizin and Dio-9 inhibited chloride uptake, but this was not accompanied by an inhibition of photosynthesis in vivo, and could not be correlated with the measured inhibition of electron flow in vitro. Low concentrations of imidazole stimulated the chloride influx in light, but there was again no effect on photosynthetic 14C02 fixation, although imidazole did uncouple electron flow in vitro. The effect of imidazole was dependent on the pH of the external solution. Increasing concentrations of carbonyl cyanide m-chlorophenylhydrazone progressively reduced the chloride influx and 14C02 fixation, and uncoupled electron flow in vitro. The work provides no evidence to support the view that chloride uptake is directly linked to electron flow rather than phosphorylation.
The Role of Ph in the Punch-Through Effect in the Electrical Characteristics of Chara Australis
Authors: Coster HGL
Published: July 2016

The role of pH in determining the electrical characteristics of the membranes of O. australis was investigated. Voltage-current characteristics were obtained with external solutions of pH 4�5-9, O. The chord resistance to hyperpolarizing currents decreased as the external pH was increased. For large hyperpolarizations (f1E < -170 m V) this effect was much greater than for small hyperpolarizations (f1E = -25 mY).
Reversion of Senescence: Effects of 2,4-Dichlorophenoxyacetic Acid and Indoleacetic Acid on Respiration, Ethylene Production, and Ripening of Banana Fruit Slices
Authors: Vendrell M
Published: July 2016

Slices cut from green, unripe fruit were treated by infiltration with aqueous solutions of 2,4�dichlorophenoxyacetic acid (2,4�D) and indoleacetic acid (lAA). 2,4.D delayed but increased the size of those peaks in respiration and ethylene production which are induced by cutting; ripening was also delayed. These effects were proportional to concentrations of 2,4.D in the range 1O-LlO-3M. Higher concentrations caused injury.
Further Studies of The Deep Freezing of Rabbit Spermatozoa In Reconstituted Skim Milk Powder
Authors: O'shea T , Wales RG
Published: July 2016

Using motility as the criterion of survival of spermatozoa, a method for the deep-frozen storage of rabbit semen was developed. The factors found to give optimum revival were the presence of 14% (v/v) dimethylsulphoxide during freezing, the inclusion of fructose in the diluent, and cooling to 5�C in an isotonic diluent while freezing in a hypertonic diluent.
Metabolism of Semen After Freezing [[ . The Aerobic Metabolism of Ram Spermatozoa Before and After Storage at ?79°C
Authors: O'shea T
Published: July 2016

The metabolism of ram spermatozoa, incubated at 37�0 shortly after ejacula-tion and after storage overnight at -79�0, was examined using various combinations of fructose, sodium lactate, sodium acetate, and sodium salts of citric acid cycle intermediates. Although freezing depressed all indices of cell metabolism, there were few qualitative differences between the metabolism by fresh or thawed semen of the various substrates. The increased oxygen uptake of thawed spermatozoa on addition of succinate was unrelated to motility and to other parameters of metabolism.
Effects of Exposure to 21 and 34°C on the Outcome of Overlapping Reproductive Cycles in the Mouse
Authors: R Pennycuik Pamela
Published: July 2016

In rodents, second and subsequent pregnancies can result either from post-partum or from post-weaning matiugs. If pregnancy results from a post-partum matiug, the gestation period overlaps with the lactation period of the previous reproductive cycle. There is some evidence that under these conditions, the viability and growth of both the suckiug and the unborn litter are affected (McCarthy 1965), although other authors could find little or no evidence of this (Krehbiel 1941; Bruce and East 1956).
Physical Environment and Symbiotic Nitrogen Fixation VII. Effect of Fluctuating Root Temperature on Nitrogen Fixation
Authors: Gibson AH
Published: July 2016

The effect of exposing nodulated plants to daily periods of high, moderate, or low root temperatures was examined, using Trifolium 8ubterraneum and three strains of Rhizobium trifolii. With strains whose nitrogen fixation was severely retarded by continuous exposure to high root temperatures, the results from treatments involving exposure of 4, 8, 12, and 20 hr/day to 30�C and continuous illumination were consistent with the effect being on the rate of nitrogen fixation, without any permanent impairment to the symbiotic system. With a 12 hr/day light period, a daily 12-hr exposure to 30�C during the dark period reduced total nitrogen fixation as much as exposure to 30�C during the light period. This indicated that the rate of nitrogen fixation during normal dark periods could be as high as that during periods of illumination. Similar conclusions were drawn from the same type of experiments involving daily exposure to moderate (14 and 16�C) root temperatures.
Identity of the Fungal Symbiont of Sirex Noctilio
Authors: PC Gaut I
Published: July 2016

The fungus associated with S. noctilio F. in Australia is identified as Amyloster-eum areolatum (Fr.) Boidin. By using a polystyrene film to prevent the breakup of the chains of arthrospores during staining, it was possible to demonstrate that the spores are homokaryotic though usually multinucleate. Viable homokaryons were established from arthrospores by using a tissue culture medium incorporating growing callus tissue of Pinus radiata. Homokaryons and heterokaryons of the S. noctilio fungus were opposed in all possible combinations against homokaryons and heterokaryons of A. chailleti'i (Pers. ex Fr.) Boidin, A.laevigatum (Fr.) Boidin, and A. areolatum, the only known species of Amylostereum. The S. noctilio fungus was interfertile only with A. areolatum, as judged by production of anastomoses, clamped mycelium, and fertile fruit bodies. Starch-gel electrophoresis showed that the soluble proteins of the S. noctilio fungus corresponded more closely with those of A. areolatum than with those of A. chailletii.
The Localization of Acid Phosphatase in the Sieve Element of Pisum
Authors: Zee S-Y
Published: July 2016

Acid phosphatase activity has been detected within the sieve-tube members of plants by many workers using the Gomori technique and light microscopy (Lester and Evert 1965; Flinn and Smith 1967). Unfortunately the limited resolution makes it difficult to determine the specific sites of activity of the reaction product of the enzyme; recent advances in histochemical techniques for electron microscopy have made it possible to investigate more specifically the sites of localization of the acid phosphatase reaction product by using the Gomori lead nitrate technique (Goldfischer, Essner, and Novikoff 1964; Catesson and Czanenski 1967; Bowen 1968; Figier 1968; Wardrop 1968).
The Dissolution and Reaccumulation of Starch Granules in Grape Vine Cane
Authors: Buttrose MS
Published: July 2016

Starch granules may be observed to break down in vivo either by corrosion spreading inwards from discrete points on the surface or by a decrease in size without change in shape due solely to surface action. The latter way may be termed reverse apposition because apposition growth of granules is observed as an increase in size without change in shape. There are grounds for suggesting the hypothesis that amylases are responsible for corrosion and some other enzyme system for reverse apposition.
The Uptake of Nitrate and Ammonium by Suceessive Zones of the Pea Radicle
Authors: Grasmanis VO , Barley KP
Published: July 2016

Measurements were made of the uptake of ammonium and nitrate by successive zones of the radicle of intact seedlings of Pisum sativum L. A modified version of the potometer designed by Gregory and Woodford (1939) was used to supply separate zones, and the amounts of nitrogen absorbed were determined with the stable isotope lON.
Energy-Transducing Reaction in Biologyical Members. I. Energy Transduction in Ion- and Electron-Exchange Polymers
Authors: Weiss DE
Published: July 2016

Theoretical and experimental studies of the properties of rubbers, and of ion-and electron-exchange polymers, show that mechanical deformation, the application of heat, adsorbing solvent or solute molecules onto the polymer chains, or changing the crosslinking alters the free energy changes of interactions occurring at ion-exchange, electron-exchange, or other adsorption sites of the polymer as a result of changing a dilation-contractile equilibrium, and provides means for the inter-conversion of mechanical, heat, osmotic, and chemical energies. In all these processes polymer entropy changes participate in the overall free energy changes of the system.
Studies on Marsupial Protein. II. Amino Acid Sequence of the -Chain of Haemoglobin from the Grey Kangaroo, Macropus Giganteus
Authors: Air GM , Thompson EOP
Published: July 2016

The amino acid sequence of the jS-chain of haemoglobin from M. giganteus has been determined. The soluble peptides formed by tryptic digestion were isolated by gel filtration, ion-exchange chromatography, and paper ionophoresis, and amino acid sequences determined by the "dansyl"-Edman procedure. Special procedures were necessary for three peptides which were insoluble.
Changes in Rate of Leakage of Potassium from Excised Disks of Apple Fruits Held at 20'c After Harvest
Authors: Lewis TL , Martin D
Published: July 2016

As early as 1928, Blackman and Parija suggested that the climacteric rise in respiration which is associated with ripening in most fruits might be due to changes in cell permeability. This view has been supported by recent observations on some tropical and subtropical fruits, viz. the avocado (Sacher 1962; Ben-Yehoshua 1964; Young and Biale 1967), the banana (Baur and Workman 1964; Sacher 1962, 1966), and the nutmeg melon (Von Abrams and Pratt 1967).
The Survival of Ram Spermatozoa Following Pellet Freezing Below ?79°C
Authors: Salamon S
Published: July 2016

Six factorial experiments were conducted to examine the survival of ram spermatozoa following pellet freezing below -79�C.
Comparisons of Leaf Water Potential and Xylem Water Potential in tomato Plants
Authors: Barrs HD , Freeman B , Blackwell J , Ceccato RD
Published: July 2016

The rapidity and convenience of the pressure chamber technique for estimating leaf water potentials, especially under field conditions, has been remarked (Boyer 1967; Kaufmann 1968a, 1968b) and demonstrated (Klepper and Ceccato 1969). However, Kaufmann (1968a) showed that it is necessary to exercise caution .in using measurements made with the pressure chamber as direct estimates of leaf water potential. Instead, he recommended that calibration curves should be drawn up for each species, relating measurements of xylem pressure potential obtained with this technique to corresponding known leaf water potentials. The present communication reports such a relation for tomato leaves, which have not previously been studied in this way. Plant age is shown to affect the relation.
Changes in Fine Structure of Root Cells from Maize Seedlings Exposed to Water Stress
Authors: Nir I , Klein S , Poljakoff-Mayber Alexandra
Published: July 2016

As previously reported (Nir et al. 1969) changes in the ultrastructure of meristematic cells were induced by exposure of detached maize root tips to water stress. The question remained whether similar fine structure changes would be induced if instead of isolated root tips, the whole seedlings were exposed to water stress. Since knowledge of the behaviour of intact seedlings is important for the understanding of drought physiology, we investigated the changes which occur in the fine structure of root cells when whole seedlings are exposed to drought.
The Effect of Cycloheximide on Cell Division in Partially Synchronized Plant Cells
Authors: Rose RJ
Published: July 2016

Cycloheximide blocked cell division at interphase, prophase, prometaphase, metaphase, and telophase in Jerusalem artichoke tuber tissue. Blocking at anaphase did not occur or was very infrequent. In any cell, the location of the block depended upon the stage of the cell cycle reached at the time of cycloheximide addition. In general, cycloheximide caused similar blocks in interphase and mitosis in cells of synchronised broad bean root tips. A reduction of mitotic frequency occurred after about 8 hr in cycloheximide, indicating a reversion of chromosome coiling.
Bacterial Blight of Vicia Sativa: Aetiology of the Disease and Identification of the Pathogen
Authors: Allen RN , Hayward AC , Halliday WJ , Fulcher Jean
Published: July 2016

A serious new disease of vetch in the north coast area of New South Wales was shown to be caused by Pseudomonas stizolobii (Wolf) Stapp. The pathogen, recorded in Australia for tho first time, was able to infect eight other species of legumes in glasshouse tests. Field diseases of Trifolium repens and Mucuna sp. caused by this organism were also recorded and isolates obtained from these sources were found to be pathogenic to vetch.
A Polysaccharide-Containing Cell Coat on Keratinizing Cells of the Romney Wool Follicle
Authors: Orwin DFG
Published: July 2016

The periodic acid-silver methenamine test revealed the presence of a polysaccharide- containing cell coat on the surfaces of keratinizing cells of the Romney wool follicle. This coat was present throughout the changes involving cellular adhesion, cell growth, and cell shape which occur before keratinization is complete. Once these changes were complete, the cell membrane, or regions close to it, and the cell coat of the cortex and the cortex cuticle cells became modified. Modifications of the cell membrane, or regions close to it, in the inner root sheath occurred on or just prior to hardening of these cells.
Keratin Fibres III. Amino Acid Analyses of Histological Components
Authors: Bradbury JH , Chapman GV , King NLR , O'shea JM
Published: July 2016

Amino acid analyses have been made of five different samples of cortical cells, 10 samples of cuticle, and 17 samples of whole fibres from various placental mammals, marsupials, and monotremes. There were no consistent differences in analyses between these three subclasses of mammals. Although there are considerable differences in amino acid analyses among the fibres from the various animals, nevertheless these differences are less than those between the analyses of whole fibres and cuticle. Thus the amino acid analyses of all keratin fibres have been averaged to give a result which is characteristic for keratin fibres. Similarly an average value is given for the amino acid analyses of cortical cells (which is very close to that of whole fibres), cuticle, and medulla.
The Occurrence of Transfer Cells in the Vascular Tissues of the Coleoptilar Node of Wheat
Authors: O'brien TP , Zee S , Swift JG
Published: July 2016

Wooding and Northcote (1965), Gunning, Pate, and Briarty (1968), Gunning and Pate (1969), and Pate and Gunning (1969) have drawn attention recently to the presence of cells with wall ingrowths in a number of sites in plants at which one might expect short-distance transport of considerable quantities of solutes. Gunning and Pate (1969) suggested that these cells be called "transfer cells" and surveyed their distribution in the leaves of a large sample of Angiosperms. These cells have not been found in the leaves of any grasses, and they have been demonstrated in the Gramineae only in the embryo sac of maize (Diboll 1968). In this paper, transfer cells are illustrated in the vascular tissue at the coleoptilar node in wheat, and the possible functions of these cells at this site are discussed.
Keratin Fibres IV. Structure of Cuticle
Authors: Bradbury JH , Leeder JD
Published: July 2016

The cuticle structure of keratin fibres of placental mammals, marsupials, and monotremes has been examined by the techniques of light microscopy and scanning electron microscopy. These techniques have been used to study both intact fibres and whole cuticle cells separated by formic acid treatment.
Interrelations Between Growth and Photosynthesis of Salt Bush (Atriplex Halimus L.) Grown in Saline Media
Authors: Gale J , Poljakoff-Mayber A
Published: July 2016

Plants of A. halimus were grown in culture solutions to which NaCl or Na2S04 was added to different concentrations. The osmotic potential of the sap, growth, morphology, and leaf gas exchange (transpiration and photosynthesis) were studied. At least three different effects of salinity were identified: (1) an increase of leaf area and succulence induced by relatively low concentrations of salt in the growth medium. This resulted in an increase of the leaf area available for transpiration and photosynthesis (and hence growth); (2) an increase of stomatal resistance to water vapour loss and C02 uptake. This tended to reduce both transpiration and photosynthesis per unit leaf area; (3) changes in mesophyll resistance to C02 uptake (r;"). Relatively low concentrations of NaCl reduced r;", but high NaCl concentrations (i.e. external osmotic potentials lower than -9 atm) and all concentrations of Na2S04 brought about an increase in r;". In addition to the above effects, salinity may have caused a hormonal imbalance as was indicated by the increased sprouting of lateral buds.
The Regulation of Stomatal Aperture in Tobacco Leaf Epidermal Strips I. The Effect of Ions
Authors: Thomas DA
Published: July 2016

A simple apparatus has been developed whereby the extent of stomatal opening on isolated epidermal strips can be monitored by measuring the flow rate of bathing solution through the stomata. This apparatus has been used to study the opening and closing response of stomata to various treatments. A supply of ions, particularly K+, was found necessary to initiate and maintain the opening of stomata in the light. In the presence of K+ stomata could be opened in the light and closed in the dark. This cycle could be repeated. The pattern of stomatal opening in the light and closing in the dark showed a similar shape with time to that shown for stomata on leaves. Similar results could be obtained in a bathing medium consisting of KH2P04-Na2HP04 buffer. The best pH found for opening was 8� O. No specificity of stomatal opening was found for the anion associated with K +. The addition of Ca2+ or Mg2+ to the bathing medium caused reductions in aperture. The extent of stomatal opening in response to the concentration of K+ in the range 0-10 mM gave a saturation curve with a concentration for half maximal opening of O� 32 mM. Increasing the concentration of K+ past 10 mM resulted in reductions of aperture.
The Regulation of Stomatal Aperture in Tobacco Leaf Epidermal Strips II. The Effect of Ouabain
Authors: Thomas DA
Published: July 2016

The K+-dependent, light-stimulated opening of stomata on tobacco and V icia faba epidermal strips was found to be rapidly reduced by low concentrations of ouabain. On removing ouabain stomatal aperture rapidly increased. This suggests that the influx of K+ into the guard cells is associated with a membrane�bound transport ATPase. Experiments with 10-5M p.chloromercuribenzoate (PCMB) and ouabain indicate that the considered transport ATPase is not markedly affected by PCMB. The stomatal opening obtained in the presence of Na+ alone is also decreased on the addition of ouabain, though ouabain does not prevent the longer-term stomatal opening which occurs in the dark in the presence of N a + alone. In the light, recovery of stomatal opening on the removal of ouabain from the bathing medium only occurred in the presence of K+. It is considered that an ATPase�linked K+ transport system could give the rapid rate of influx that would be necessary to bring about stomatal opening in the times observed. The presence of an ATPase transport system would give an evolutionary link between the stomatal control mechanism and that associated with the function of other excitable cells such as nerve and muscle.
Synthesis and Breakdown of ß-L,3-Glucan in Euglena Gracilis During Growth and Carbon Depletion
Authors: R Dwyer Margaret , Smydzuk J , M Smillie Robert
Published: July 2016

Cellular levels of the reserve carbohydrate of the Z strain of E. gracilis, f3-1,3-glucan (paramylon), were determined during heterotrophic growth in the dark and in the light. During growth in the dark the f3-1,3-glucan content exceeded 6 mg per 107 cells, but most of this was not readily available for cell growth and division. Towards the end of the growth phase the f3-1,3-glucan content fell to 2-4 mg per 107 cells but the total f3-1,3-glucan content of the culture remained about the same. After division stopped the f3-1,3-glucan was utilized only slowly. Similarly, when rapidly growing cells were transferred to a medium lacking a source of carbon for growth, cell division continued for several hours but ceased when the f3-1,3-glucan content had fallen to about 2 mg/107 cells.
Nuclear Distribution in Vegetative Cells of Ophiobolus Graminis and other Cereal Root Pathogens
Authors: Mills SC , Scott TW , Russell GR , Smith RM
Published: July 2016

Difficulty is 'sometimes experienced in distinguishing between O. graminis and sterile fungi which form "Ophiobolus-like" runner hyphae on cereal roots. However, it is possible that nuclear distribution in mycelium may prove a differential character as different distributions have already been reported for O. graminis (Chambers and Flentje 1967) and a cereal root-attacking strain of Rhizoctonia solani (Flentje, Stretton, and Hawn 1963). This paper, therefore, describes comparisons of nuclear distribution in O. graminis and several other cereal root pathogens including a sterile fungus which formed Ophiobolus-like runner hyphae.
Hydrogenation of C18 Unsaturated Fatty Acids by Pure Cultures of a Rumen Micrococcus
Authors: Mills SC , Scott TW , Russell GR , Smith RM
Published: July 2016

Approximately 70% of the fatty acids present in plant lipids are unsaturated; the major component is cis-9,cis-12,cis-15-octadecatrienoic acid (Garton 1963). After ingestion by ruminants, these acids are readily hydrogenated by microorganisms in the rumen to form a complex mixture of positional and geometrical C18 isomers (Shorland et al. 1957; Ward, Scott, and Dawson 1964; Wilde and Dawson 1966; Kemp and Dawson 1968).
Sites of Action of Plant Growth Retardants on Cholesterol Biosynthesis by Cell-Free Rat Liver .Preparations
Authors: Paleg LG
Published: July 2016

Experiments with cell-free preparations of rat liver indicate that of the plant growth retardants Phosfon B, Phosfon D, B995, COlI, and Amo 1618 all but B995 inhibit at least one step between acetate and mevalonate in cholesterol biosynthesis. The results also demonstrate that all of the retardants, including B995, inhibit at least one step between mevalonate and cholesterol, and that several of them act at different points along this part of the biosynthetic sequence.
Inositol Phosphate Phosphatases of Microbiological Origin. Inositol Phosphate Intermediates in the Dephosphorylation of the Hexaphosphates of Myo-Inositol, Scyllo-Inositol, and D-Chiro-Inositol by a Bacterial (Pseudomonas sp.) Phytase
Authors: Cosgrove DJ
Published: July 2016

Inositol phosphate n;termediates formed during the enzymic (bacterial phytase) dephosphorylation of the hexaphosphates of myo-, scyllo-, and D-chiroinositol have been isolated by means of ion-exchange chromatography. Hydrolysis of myo-inositol hexaphosphate is believed to proceed via D-myo-inositol 1,2,4,5,6- pentaphosphate, D-myo-inositol 1,2,5,6-tetraphosphate, D-myo-inositol 1,2,5- or 1,2,6-triphosphate or both, D-myo-inositol 1,2-diphosphate, and finally myoinositol 2-monophosphate.
Studies on Ovalbumin V. The Amino Acid Composition and Some Properties of Chicken, Duck, and Turkey Ovalbumins
Authors: SmIth MB , F Back Joan
Published: July 2016

The ovalbumins from chicken, duck, and turkey eggs were prepared by ammonium sulphate fractionation and purified by isoelectric focusing in a pH gradient from 3 to 6. Amino acid analyses show a closer relationship between turkey and chicken ovalbumins than between duck and chicken ovalbumins.
Fertilization and Survival of Fertilized Eggs in the Ewe Following Surgical Insemination at Various Times After the Onset of Oestrus
Authors: D Killeen I , Moore NW
Published: July 2016

Two experiments are described in which fertilization and development of fertilized eggs to lambs were studied following cervical and surgical (tubal and uterine) insemination of ewes at various times after the onset of oestrus. The experiments also provided information on the time of ovulation and on the fertilizable life of the ovine egg.
Oxygen and the Ecology of Armillariella Elegans Heim
Authors: Smith AM , Griffin DM
Published: July 2016

Oxygen is important in the ecology of A. elegans because it affects both the rate of growth and form ofrhizomorphs. Maximum growth is dependent on high rates of oxygen diffusion within the central canals of rhizomorphs but partial pressures of oxygen in excess of 0�04 atm in contact with the outside surfaces of rhizomorphs are inhibitory.
Effect of Composition of the Thawing Solutions on Survival of Ram Spermatozoa Frozen by the Pellet Method
Authors: Salamon S , Brandon MR
Published: July 2016

Six factorial experiments were conducted to examine the effects of thawing solutions consisting of non-electrolyte or of a combination of non-electrolyte and sodium citrate on the survival of ram spermatozoa pellet frozen with a raffinose-citrate diluent.
Inositol Phosphate Phosphatases of Microbiological Origin.Observations on the Nature of the Active Centre of a Bacterial (Pseudomonas Sp.) Phytase
Authors: Irving GCJ , Cosgrove DJ
Published: July 2016

The pentaphosphates produced by a bacterial phytase acting on myo- and I,-ckiro-inositol hexaphosphates as substrates were identified by ion-exchange chromatography. On the basis of the structures of these pentaphosphates and the previously published properties of the bacterial phytase, a simple model for the active centre of the enzyme is proposed which is capable of explaining the intermediates, as far as the diphosphate stage, isolated by Cosgrove from the hydl'olysates of myo�, D.ckiro-, and 8cyllo-inositol hexaphosphates due to the action of this enzyme. With slight modification this model for the active centre is also capable of explaining, as far as the diphosphate stage, the intermediates isolated by Tomlinson and Ballou from the hydrolysate of myo�inositol hexaphosphate by wheat-bran phytase
Interactions of Processes for Accumulation of Salt and Sugar in Barley Plants
Authors: Pitman MG , Mowat Julie , Nair Helen
Published: July 2016

Low-salt barley plants contain low salt and high sugar levels; high-salt plants contain high salt but low sugar levels. It is shown that salt inhibits glucose transport into the cell and it is suggested that the low sugar level in high-salt plants is due to this inhibition. During uptake of salt by low -salt roots the sugar level falls, and rates of salt transport and respiration are both correlated with sugar level in the root. It is suggested that due to the high sugar level, rates of uptake of salt to low-salt roots may be exaggerated when compared with high-salt roots. The dependence on metabolic status has been ignored in kinetic studies of ion transport
The Use of Short-Term and Quasi-Steady Influx in Estimating Plasmalemma and Tonoplast Influx in Barley Root Cells at Various External and Internal Chloride Concentrations
Authors: Cram WJ , Laties GG
Published: July 2016

Chloride influx measured with 36Cl over a 10 min loading period followed by a 5 min wash in inactive solution is used as an estimate of influx across the plasmalemma in barley roots. Chloride influx measured over a 60 min loading period followed by a 30 min wash is used as an estimate of the quasi-steady influx from the external solution to the vacuole
Sodium and Potassium Influx into Citrus Leaf Slices
Authors: Smith FA , Robinson JB
Published: July 2016

The influxes of sodium and potassium have been measured in slices of mature citrus leaves, using 22Na and 42K as tracers. External concentrations were 0�03-100 mM (sodium) and 0�I-100 mM (potassium). The sodium influx was always less than the potassium influx, for any given external concentration. In neither case was the influx increased by light. There was no effect on the influxes when chloride ions in the experimental solutions were replaced by sulphate ions.
Inhibition of Ethylene Production in Banana Fruit Tissue by Ethylene Treatment
Authors: Vendrell M , Mcglasson WB
Published: July 2016

A temporary ethylene treatment, sufficient to stimulate ripening in banana fruit tissue, partly suppresses endogenous ethylene production and the evolution of ethylene from methionine. The production of endogenous ethylene does not return to rates normal for naturally ripening fruit after the exogenous ethylene is removed. The extent of inhibition is related to the concentration of applied ethylene up to 5-10 p.p.m., and to the duration of treatment within the period 12 hI' to 3 days. Other characteristics of ripening appear to develop normally, except in the shorter treatments, where respiration shows a lower climacteric peak and chlorophyll breakdown is delayed.
Ultrastructure of Nuclear Division in Paramecium Aurelia II. Amitosis of the Macronucleus
Authors: Stevenson I , Lloyd FP
Published: July 2016

Ultrastructural details of macronuclear amitosis in the ciliate P. aurelia are
described. During amitosis the nuclear membrane remains intact, and there are no
changes in the appearance of the nucleoli and chromatin bodies of the macronucleus.
At the commencement of amitosis the nucleus adopts a smoother outline and a
position in the cell opposite the gullet. This usually occurs at the time when the
micronuclei are in metaphase of mitosis.
The Early Stages of Grain Development in Wheat: Response to Water Stress in a Single Variety
Authors: Wardlaw IF
Published: July 2016

In wheat (Triticum ae8tivum cv. Gabo) a temporary water deficit in the first
7 days following anthesis significantly reduced the final grain weight per ear. A
reduction in seed set in response to stress was associated with an initially greater
rate of development of the remaining grains, with an enhanced rate of cell division in
the endosperm. Relative turgidity measurements indicated that the stress applied
did not significantly reduce grain water content, although the ear structure showed
some water loss, and the stem and flag leaf blade were quite severely stressed. Th!'
greater desiccation of the leaf and stem in comparison with the ear was reflected in
the lower rate of photosynthesis of these organs under stress conditions.
14c-Labelled Material Leached From the Rhizosphere of Plants Supplied with 14co2
Authors: Martin JK
Published: July 2016

14C, supplied to plant tops as 14C02, was recovered in water-soluble organic
material when pots with wheat, clover, or ryegrass growing in a podzolic sand were
leached with distilled water at weekly intervals following exposure to 14C02. Similar
material was recovered from unplanted controls. Percentage recoveries of total
14C supplied were ryegrass 0�41, clover 0,30, wheat 0,19, control 0�14. 14C was
leached from all pots at a steady rate up to 10 weeks following cessation of exposure
to 14C02.
Influence of Plant Species and Plant Age on the Rhizosphere Microflora
Authors: Martin JK
Published: July 2016

Significant differences were observed in the number of bacteria present in water leachates from pots containing different plant species (wheat, subterranean clover, ryegrass), and within a plant species, during growth from seedlings to the formation of mature seed. Bactel�ial numbels in the leachates reached a peak which coincided with flowering for each plant species. The peak values for wheat, clover, and ryegrass, respectively, were 33, 77, and 99 times the number of bacteria present in leachates from control pots without plants. Subsequently, the number of bacteria in leachates from wheat pots decreased until they were not significantly different from the controls. There was a lesser decrease for the clover and no significant decrease for the ryegrass treatments.
The Effect of Subtrate Availability on Cellulolytic Enzyme Production by Selected Wood-Rotting Microorganisms
Authors: Greaves H
Published: July 2016

Extracellular cellulases have been produced in shake cultures of Polystictus
ver8icolor, Fornes anno8U8, Lenzites trabea, Poria monticola, and Bacillus polymyxa,
using substrates of cellulose powder and river birch woodmeal. The comparative
effect on enzyme production of wet and dry ball milling of the substrates has been
examined. Studies were also made to establish the relative amounts of enzyme
diffused, bound, or adsorbed during production and the influence of pH on cellulase
activity. It was found that wet ball milling reduces the particle size of both materials
more rapidly than dry ball milling. There was an overall increase in enzyme released
as the particle size of the substrate decreased, but no correlation was established
between this phenomenon and growth of the microorganisms. Dry milled substrates
of comparable particle size produced higher yields of cellulases than the wet milled
substrates, Lenzites trabea being more active in enzyme production than any of the
other organisms. Diffusion of cellulases occurred more readily in the brown rot fungi
than in the two white rot microorganisms and a higher percentage of enzyme remained
bound with the latter group.
Quantitative Determination of Cysteine and Cystine in Peptides and Proteins Using Hydriodic Acid
Authors: Inglis AS , Nicholls PW , Roxburgh CM
Published: July 2016

Determination of the composition of proteins by amino acid analysis after
hydrochloric acid hydrolysis is unsatisfactory for cystine which is not all recoverable.
When proteins were hydrolysed in hydriodic acid, half-cystine was released quickly
and without measurable loss as cystine with freshly distilled acid and as cystine plus
cysteine with hydriodic acid containing hypophosphorous acid_ The necessary
alterations to the normal operating conditions of an amino acid analyser to enable
the resolution of cysteine from proline are discussed. This procedure for cystine
analysis provides a simple alternative to determinations involving chemical
modification of the amino acid.
Identification of [75se]Selenomethionine in Ewe Milk Protein Following the Intraruminal Administration of Na75seo3 as a Single Oral Dose
Authors: Godwin KO , Handreck KA , N Fuss Christine
Published: July 2016

Inorganic selenium, as Na275Se03, was given intraruminally to lactating
ewes, and for 48 hr afterwards samples of blood and milk were taken regularly.
The animals were then slaughtered and tissues taken for further analysis. Evidence
is presented, based on isolation techniques using Sephadex chromatography and
gas-liquid chromatography, that 75Se is incorporated into milk proteins as selenomethionine_
It is estimated that at least 3% of the selenium that enters the milk,
from this inorganic source, is present as bound selenomethionine. This is a minimal
value, since it has been shown that selenomethionine is easily degraded during a
number of the isolation procedures.
Factors Affecting Lipid Output and Flow of Thoracic Duct Lymph in Newborn Calves
Authors: Gooden JM , Brandon MR , Hartmann PE , Lascelles AK
Published: July 2016

The factors affecting lipid absorption in unanaesthetized calves less than
24 hr old have been studied by comparing the output of lipid in the thoracic duct
lymph of calves fed one of the following diets: (1) colostrum, in which the colostral fat
was replaced with milk fat globules; (2) milk; (3) colostral whey containing milk
fat globules; (4) isotonic saline containing milk fat globules. The animals were fed
after they had recovered sufficiently from the operation to stand and suck from a
nipple feeder.
Adenine Nucleotide Levels in Cells of the Marine Alga, Griffithsia
Authors: Mcc Lilley R , Hope AB
Published: July 2016

The ionic relations of giant cells of the marine red alga Griffithsia are determined,
in part, by an active inward transport of Cl- ions that is stimulated by light (Findlay,
Hope, and Williams 1969, 1970). The light-dependent component of this active Clinflux
is affected by metabolic inhibitors in a manner suggesting that the energy
supply for it is derived from non-cyclic photophosphorylation (Lilley and Hope
1971).
Haploid Arabidopsis Thaliana Callus and Plants From Anther Culture
Authors: Gresshoff PM , Doy CH
Published: July 2016

Haploid callus and plants were cultured from the anthers of diploid A. thaliana. This depends on removing anthers during late prophase of meiosis, selecting a genotype favouring callus formation from dividing sporocytes on a high auxin-low kinetin concentration, fully defined medium, then inducing differentiation by transfer to a low auxin-high kinetin concentration, fully defined medium, with a light-dark cycle. Attempts to produce embryoids directly from' anthers were unsuccessful. The view that our approach may have Ii. more general application is discussed in relation to the work of others and our culture of haploid callus and plantlets from tomato (LycoperBicon eBculentum) and haploid callus from barley (Hordeum vulgare).