bluuebunny/crossref_metadata_2025 huggingface dataset:
Uptake and Transport of Ions in Barley Seedlings II. Evidence for Two Active Stages in Transport to the Shoot
Authors: Pitman MG
Published: July 2016

For some purposes it is adequate to explain the exudation of salt from roots, and the transport from root to shoot, as the result of a single active transport at the outer surface of the cells of the root. This paper shows that it is also necessary to have a second, active transport prior to entry to the xylem. Support for this model is based on a variety of observations. Tracer uptake interpreted on a symplast model is investigated experimentally and tested by comparison with simulated properties of the system. The effects of CCCP on uptake and transport are related to this model and compared with effects of low salt content on transport and accumulation. The behaviour of excised roots is also compared with the behaviour of whole plants.
A Field Experiment to Assess the Role of Parainfluenza Type 3 Virus in Pneumonia in a Flock of Sheep in Victoria
Authors: D St George T , Liefman CE
Published: July 2016

A flock of 33 lambs born to ewes with neutralizing antibody to parainfluenza type 3 (PI3) virus was run with a flock of approximately 150 other lambs and their mothers. When bled shortly after birth, lOO% of the 33 lambs had maternal anti-body to PI3 virus. Four months later, the proportion h!lod fallen to 22%, about which time a natural infection with PI3 virus occurred in the flock as judged by subsequent appearance in the sera of PI3 serum neutralizing antibody.
Fluoroacetic acid Biosynthesis: a Proposed Mechanism
Authors: Mead RJ , Segal W
Published: July 2016

A mechanism for the biosynthesis of fluoroacetic acid is presented. This is based on a correlation of phytochemical and taxonomic data together with the established function of pyridoxal phosphate in general amino acid metabolism. Evidence for this hypothesis is based on the reported incorporation of a wide range of synthetic nucleophiles into corresponding j3-substituted alanines by plant homo-genates. Fluoride ion is considered to be an acceptable nucleophile for a non-specific enzyme synthesizing a range of j3-substituted alanines, many of which occur in plants elaborating fluoroacetic acid.
The Output of Spermatozoa in Rams I. Relationship with Testicular Output of Spermatozoa and the Effect of Ejaculations
Authors: Lino BF , Braden AWH
Published: July 2016

The mean daily output of spermatozoa was estimated for each of eight Merino rams from the numbers of spermatozoa eliminated from the urogenital tract both in the urine and in spontaneous discharges over 20 days (DSOU) and by doubling the number of spermatozoa collected daily from one testis by a rete testis catheter (DSOT). The two estimates (DSOU and DSOT) were highly correlated (r = 0�999), but the DSOU was usually a little lower than the DSOT. The mean difference was 3�4%.
Vascular Tissue and Transfer Cell Distribution in the Rice Spikelet
Authors: Zee S-Y
Published: July 2016

Recently Zee and O'Brien (1971a, 1971b) have described the distribution of the vascular tissue and transfer cell in the nodes of the spikelet axis of wheat and millet. From those reports it was clear that the distribution of the vascular system and its associated transfer cells could be quite variable. In this communication another variation found in the nodal region of the spikelet of the rice plant will be described.
Activation Energy Analysis and Limiting Factors in Photosynthesis
Authors: Gifford RM , Musgrave RB
Published: July 2016

It has been proposed that activation energies of CO2 exchange obtained from Arrhenius plots of the temperature response of leaf CO2 exchange rates (or the equivalent QIO analysis) should elucidate the rate-limiting processes. Chmora and Oya (1967), for example, suggest that a QlO (15-25�0) of about 1 for maize photo-synthesis at low light and low CO2 concentration implies photochemical reactions are limiting, at high light and high CO2 a QIO of 1 �6 implies enzyme reactions are limiting, whilst at high light and low CO2 a QlO of 1� 25 suggests diffusion is limiting. Bjorkman, Nobs, and Hiesey (1969) surmise that for Mimulus sp. at 0�07% CO2 the coincidence of QIO (15-30�0) for both CO2 exchange (at 1'5% oxygen and saturating light) and extracted carboxydismutase (QlO = 2�7-3�3) could reflect a causal relationship. Charles-Edwards and Charles-Edwards (1970) find that for clones of three grass species there is a clustering of the determinations of activation energy around certain values. It is suggested that each such value may be characteristic of a certain rate-limiting process.
Hormonal Modification of Plant Response to Water Stress
Authors: Mizrahi Y , Richmond AE
Published: July 2016

Addition of either kinetin or abscisic acid (ABA) to the root medium of tobacco plants grown in culture solution greatly modified their response to different types of root stresses that were applied 48 hr after the addition of the hormones.
Further Evidence on Multiple-Peak Epistasis in Drosophila Melanogaster
Authors: Nassar RF
Published: July 2016

A selection experiment was conducted to test the hypothesis of incompatibility (Fraser, Erway, and Brenton 1968) between the sc+ and the x-vert genetic systems affecting scutellar bristle number in D. melanogaster.
The Time Course of Embryonic Resorption in the Ewe
Authors: Thwaites CJ
Published: July 2016

Groups of ewes were autopsied at intervals after colchicine� induced embryonic death, or at the time of return to service. Pregnant ewes treated with colchicine on days 13, 15, 17, and 19 returned to service after intervals of 7�0, 10�3, 18�2, and 21�0 days respectively.
Erythrocyte Glutathione Polymorphism in Sheep
Authors: Agar NS , Roberts J , Evans JV
Published: July 2016

Reduced glutathione (GSH) levels of erythrocytes were determined in five sheep breeds. The Merino breed had a higher incidence of low GSH animals than the other breeds tested. High GSH type animals of the Border Leicester breed had a significantly lower mean GSH level than did higher GSH animals of the other breeds.
The External Location of Phosphatase Activity in Phosphorus-Deficient Spirodela Oligorrhiza
Authors: Bieleski RL , Johnson PN
Published: July 2016

Phosphorus deficiency (P deficiency) caused a 10-20�fold increase in phos-phatase activity of S. oligorrhiza homogenates. Specific staining showed that phosphatase in control plants was located primarily in and around the vascular strands, and in P�deficient plants it was located in the epidermis of the root and undersurface of the frond. Dissection experiments showed that roots of P�deficient plants contained a disproportionately high phosphatase activity. When plant and root homogenates were fractionated, phosphatase activity was recovered in the supernatant rather than in any cell particle fraction. However, intact plants released very little phosphatase to the external medium.
Heterokaryon Formation and Genetic Recombination Between Auxotrophic and Morphological Mutants of Thanatephorus Cucumeris
Authors: Dodman RL
Published: July 2016

Two auxotrophic mutants of T. cucumeris, one requiring nitrite and the other nicotinic acid, were obtained by irradiation of basidiospores with ultraviolet light. The deficiency was caused by a single-gene mutation in each case. Both mutants were fertile.
Oestrous Frequency and Incidence of Pregnancy in Mice Housed Singly and in Groups at 4, 21, and 33°C
Authors: R Pennycuik Pamela
Published: July 2016

Oestrous cycle frequency was measured in mice housed singly, in mice housed in groups, and in grouped females in olfactory and tactile contact with a male. The animals were kept at 4,21, or 33�0. When the mice were housed singly, all groups had between 2�2 and 3�5 cycles in the 16 days period of observation. The small differences between the groups were not significant. Grouping (15 mice per cage) caused a significant reduction in oestrous frequency at all three temperatures, but the differences between the temperature groups were not significant. Introduction of a caged male into the group of females had no effect on oestrous frequency at 4 and 21 �0. At 33�0 frequency increased and the difference between the temperature groups became significant. When the males were released into the cages of grouped females the incidence of pregnancy in the group at 33�0 was seven times greater than that at 4 or 21 �0.
Oospore Production in Phytophthora Cinnamomi in the Presence of Trichoderma Koningii
Authors: Pratt BH , Sedgley JH , Heather WA , Shepherd CJ
Published: July 2016

The soil-borne fungus Phytophthora cinnamomi Rands is a particularly impor-tant pathogen in Australia because of its consistent association with root-rot disease of a wide variety of exotic and native plant species. It was thought originally to have been introduced from south-east Asia (Crandall and Gravatt 1967), but evidence recently obtained (Pratt, Heather, and Shepherd, unpublished data), suggests that it may be indigenous to eastern Australia and may have been partly instrumental in determining the distribution of certain susceptible species, particularly Eucalyptu8 spp.
Keratin Fibres VII. Proteins of the Histological Components of Kangaroo Fibres
Authors: Bradbury JH , O'shea JM
Published: July 2016

Cortical cells, cuticle, and an impure sample of medulla were prepared from kangaroo fibres by vigorous agitation in formic acid at room temperatme, which control experiments show causes no degradation of soluble. high-or low-sulphur proteins. Many reductive extraction procedures were examined and the best method appears to be treatment with O� 2M thioglycollate at pH 11� 0 in 8M urea for 3 hr at 40�C, followed by coupling with iodoacetate. The high-and low-sulphur proteins from kangaroo fibres and its histological components were prepared and examined by gel filtration using Agarose in 8M urea at pH 8 with a column calibrated for measurement of molecular weight.
Selection for Sexual Dimorphism in Body Weight of Mice
Authors: Eisen EJ , Hanrahan JP
Published: July 2016

A general prediction formula was developed to inolude ma.ternal effeots in seleotion for sexual dimorphism. This prediotion equation was extended to the oase of within-family seleotion.
Aspects of Potassium Accumulation by Stomata of Vicla Faba
Authors: Fischer RA
Published: July 2016

Potassium accumulation by guard cells during the light opening of V. Jaba stomata in epidermal strips was determined quantitatively with 42K and 86Rb tracers. The sodium cobaltinitrite stain for potassium was also used. Particular attention was paid to errors arising from the presence of intact epidermal cells.
Metabolism of Cystine by Merino Sheep Genetically Different in Wool Production I. Comparison of the Entry Rates of Cystine in Sheep From Flocks Selectively Bred for High and Low Fleece Weight
Authors: Williams AJ , Leng RA , Stephenson SK
Published: July 2016

The rates of entry of cystine into the extracellular compartment, and the concentrations of cystine in this compartment, were measured during 12-14 hr infusions ofL-[35S]cystine in Peppin Merino ewes_ The ewes were sampled from flocks selectively bred for high or low clean fleece weight per head; and were fed either 500 or 1100 g of chaffed lucerne hay daily during the experiment.
Estimation of the Total Entry Rate and Resynthesis of Glucose in Sheep Using Glucoses Uniformly Labelled With 14C and Variously Labelled With 3H
Authors: Judson GJ , Leng RA
Published: July 2016

Comparisons have been made of [6_3H]-, [3-3H]-, and [2-3H]glucose with [U-14C]glucose for measuring parameters of glucose metabolism in sheep given their daily ration in 24 equal amounts at hourly intervals. The specific radioactivity (R) of plasma glucose was measured at frequent intervals from 0 to 10 hr and 0 to 32 hr after the start of a constant infusion. or single injection, of mixtures of these isotopes respectively.
Relationships Between Milk and Milk Fat Composition and Trans-Lactation Changes in Mammary Gland Enzyme Activities in Grazing Cattle
Authors: Currie WB
Published: July 2016

Ohanges in milk and milk fat composition during complete lactations of four grazing cows are described. Correlations among the proportions of pairs of milk fat fatty acids were interpreted to indicate that fatty acids were of three groups-those reaching the gland preformed as blood lipids, those synthesized de novo in the gland, and a fraction, chiefly palmitic' acid, derived from both sources. The pro-portions of all groups of acids varied in an erratic manner compared with steady changes observed in other studies with cows on controlled feeding.
Photosynthetic Characteristics of Modern and Primitive Wheat Species in Relation to Ontogeny and Adaptation to Light
Authors: Dunstone RL , Gifford RM , Evans LT
Published: July 2016

Some characteristics of photosynthesis in seven species of Triticum and two of Aegilops were examined. Differences between species in the rate of net photosynthesis per unit area were more pronounced in later formed leaves than in earlier ones, flag leaves showing the greatest range of photosynthesis rates.
Preparation of Rolled Epidermis of Vicia Faba L. So That Stomata are the Only Viable Cells: Analysis of Guard Cell Potassium by Flame Photometry
Authors: Allaway WG , Hsiao TC
Published: July 2016

A rolling technique is described with which cells in epidermal strips of V. faba were differentially broken so that only guard cells remained alive and functional. In rolled epidermis potassium was retained only in live guard cells, as judged by staining with cobaltinitrite.
Toxin Production by Pseudomonas Tolaasii Paine
Authors: Nair NG , Fahy PC
Published: July 2016

Evidence is presented for the production of toxin in vitro and in vivo by P. tolaasii. Nutrient broth suspensions of P. tolaasii placed on detached mushroom sporophores but separated by a dialysis membrane caused brown discoloration and slightly sunken lesions.
Ultrastructure of the Obligately Anaerobic Bacteria Clostridium Kluyveri and Cl. Acetobutylicum
Authors: Cho KY , Doy CH
Published: July 2016

The morphology of Cl. kluyveri is compared with that of CI. acetobutylicum. The multilayered cell wall of both organisms differ in the number of layers and total thickness.
Dehydration of Macromolecules I. Effect of Dehydration-Rehydration on Indoleacetic Acid Oxidase, Ribonuclease, Ribulosediphosphate Carboxylase, and Ketose-1-Phosphate Aldolase
Authors: Darbyshire B , Steer BT
Published: July 2016

A pressure-membrane technique has been developed to physically manipulate the water potential of in vitro enzyme preparations. Enzyme preparations were subjected to a range of water potentials using this technique.
Acute Effects of Actinomycin D on the Binding of Tritiated Oestradiol by the Mouse Vagina
Authors: Stone GM
Published: July 2016

Mice received an intravaginal injection of oestradiol-17 P (Ez) followed at varying times by an intravaginal injection of actinomycin D.
Comparative Efficiency of Development Under Cold Stress of the Tropical Legumes Lotononis Bainesii Baker and Stylosanthes Humilis H.B.K
Authors: Gates CT
Published: July 2016

The efficiency of development of L. bainesii and S. humilis in response to increasing, specific amounts of cold stress was compared. The plants were grown under controlled environment with favourable lighting and day length regime typical of the advancing autumn season in subtropical regions.
Cellular Location and Concentration of Leghaemoglobin in Soybean Root Nodules
Authors: Bergersen FJ , Goodchild DJ
Published: July 2016

The reaction of leghaemoglobin (Lb) with oxidized 3,3'-diaminobenzidine has been used to demonstrate the localization of this haemoprotein within the membrane envelopes surrounding the bacteroids in soybean root nodule cells. In fresh tissue sections mounted in a modified Honda medium, the reagent stained the envelope contents a brick-red colour.
Phospholipid of an Extremely Halophilic Bacterium, Sarcina Morrhuae
Authors: Woodrow GC , TCheung H , Y Cho K
Published: July 2016

The major phospholipid of the extremely halophilic coccus, S. morrhuae, was purified and compared with the major phospholipid of the extremely halophilic rod, Halobacterium cutirubrum.
Studies on Wheat Endosperm I. Chemical Composition and Ultrastructure of the Cell Walls
Authors: JMares D , Stone BA
Published: July 2016

A method is described for the isolation of wheat endosperm cell walls free from non-endospermic cell walls in a 70 % ethanol medium which prevents the loss of watersoluble polymeric components.
Effects of Human Chorionic Gonadotrophin on the Incorporation of Uridine into Nucleotide Pools and Ribonucleic Acid in the Reproductive Tract of the Rabbit Doe
Authors: O'shea T
Published: July 2016

The effects of injection of human chorionic gonadotrophin, and of a previous ovulation, on the in vivo incorporation of [5- 3H]uridine into ribonucleic acid by the reproductive tract of oestrus does have been observed.
Effect of Oestradiol Benzoate on Biliary Phospholipids in the Rat
Authors: Holloway RH , Heath T
Published: July 2016

Bile was collected from conscious, ovariectomized, young female rats which had been treated with either oestradiol benzoate or peanut oil for 3 weeks. L-[Me-14C]Methionine was given intravenously immediately before collection of bile was started.
Gas Exchange in Plant Leaves Having Different Transfer Resistances Through Their Two Surfaces
Authors: Jones HG
Published: July 2016

An existing model for the internal pathways of gas� exchange in anisolateral leaves is extended so as to include the feedback effects that different gas-exchange rates through the two surfaces of a leaf can have on the concentration differences driving the exchange. This "concentration effect" is analysed in detail, and graphs are presented which can be used to estimate the magnitude of error in estimates of the intracellular resistance to CO2 uptake obtained from total leaf gas-exchange data.
An Exploration of the Carbon Economy of the Tobacco Plant I. Inferences From a Simulation
Authors: Hackett C
Published: July 2016

The question of whether photosynthesis may frequently be suppressed in the tobacco plant due to lack of demand for assimilates was examined using simulation techniques.
Changes in the Tricarboxylic acid Cycle Acids in Potatoes After Anaerobiosis
Authors: Aziz khan MA
Published: July 2016

Potatoes were subjected to anaerobiosis and then returned to air. Citrate was estimated in three experiments and malate in one. Citrate increased slightly in air after nitrogen in two experiments but not in the third. There was also a small increase in malate. From these results no firm conclusion was drawn as to whether the turnover rate in the tricarboxylic acid cycle had increased. However, the lost lactate which was unaccounted for as increased CO. output during recovery from anaerobiosis was less than the observed increases in citrate and malate contents in two experiments.
Gene Frequencies in the Domestic Cats of Adelaide
Authors: Clark JM
Published: July 2016

A survey of 600 stray cats from industrial-urban areas of Adelaide was conducted and the frequencies of some genes controlling coat colour were determined. The sample fitted a I : 1 sex ratio and comparison of observed and expected phenotypes at the orange locus established that the population was panmictic. The frequencies for d (0�326) and S (0�295) were significantly different from those in another area in Australia. A possible reason for this difference, based on different human population origins and preferences, is proposed. The frequencies of /, a, W, tb , and 0 did not differ greatly from those in other areas in Australia.
Incidence of Gaeumannomyces Graminis Var. Tritici in Consecutive Wheat Crops
Authors: Mac Nish GC , Dodman RL
Published: July 2016

A mapping technique based on an "incidence-yield" regression was used to study the incidence of G. graminis var. tritici in consecutive wheat crops at two locations in South Australia. At both locations there were only small differences between the two years, although at Turretfield (third and fourth crops) there was a tendency for highincidence areas to contract, while at Ceduna (second and third crops) disease incidence tended to increase.
Survival of Gaeumannomyces Graminis Var. Tritici in the Field Soil Stored In Controlled Environments
Authors: Mac Nish GC
Published: July 2016

A bioassay was used to study the effect of various storage treatments on the survival of G. graminis var. tritici in soil cores removed from a take-all patch. There was no significant change in the incidence of the fungus when the soil was maintained either dry (-250 to -980 bars) and cool (15�C), or moist (-4'0 to -7,0 bars) and cool (15�C). When maintained very dry (-980 bars or less) and hot (35�C) or wet (-0'1 to -0,2 bar) and cool (15�C) there was a significant reduction in disease incidence, but considerable levels of viable fungus were still present after 45 weeks storage. Only in wet hot soil (-0'1 to -0,2 bar and 35�C) was the fungus eliminated rapidly.
Genetic Influences on Mouse Growth at 23 and 32°C
Authors: Garrard G , Harrison GA , Weiner JS
Published: July 2016

Two inbred strains of mice and the reciprocal Fl hybrids between them were reared in a temperate or in a hot humid environment. There was an age-related environmental effect on the rate of increase in body weight. Between 2 and 5 weeks the rate� of weight gain was more rapid in the heat but at all other ages weight gain was more rapid in the temperate conditions. Periods of rapid growth were associated with low intra-strain variation in body weight.
A New Variety of Milky Disease, Bacillus popilliae var. rhopaea, From Rhopaea verreauxi
Authors: Milner RJ
Published: July 2016

A variety of B. popilliae was found to cause milky disease in R. verreauxi populations in the Ebor-Dorrigo region ofN.S.W. Only the closely related species R. verreauxi, R. morbillosa and Othnonius batesi were susceptible per os, while the taxonomically more distant species Sericesthis nigrolineata, S. geminata and Anop/ognathus porosus were resistant. At sporulation both a spore (2' 4 by 1� 2 .urn) and a parasporal body (I . 2 by O' 8 Jlm) are formed within the sporangium. Growth on solid J medium was sparse with a maximum colony size 2 mm in diameter under aerobic conditions; under anaerobic conditions growth was reduced. Growth was optimal at 25�C and pH 7� 5. The in vitro temperature range was 15-32�C whilst in vivo the range for spore formation was 16-30�C. Growth in vitro was solely vegetative and all attempts to induce sporulation failed. Trehalose, glucose, sucrose, mannose and maltose were utilized, resulting in acid production. Vegetative cells were normally non-motile and always catalase negative. In aqueous suspension spores survived over 60 min at 84�C but only 5 min at 94 �C.
The Phenogenetics of a Super-suppressor in Drosophila melanogaster IV. Sub-phenotype Interactions
Authors: Lee GLG
Published: July 2016

The existence of a mutant in D. melanogasler that has interactive phenotypes with several SU(HW)2- suppressible mutants that also have other suppressors has permitted the division of suppressor genes into two classes. The first class, of which SU(HW)2 is the only established member, are characterized by exerting their effect during the information transfer process.
Genetic and Enzymatic Experiments relating to the Quaternary Structure of ß-Galactosidase
Authors: Langridge J
Published: July 2016

The quaternary structure of f:!-galactosidase, which consists of four identical subunits, has been studied by the isolation and characterization of appropriate mutants of Escherichia coli. Of 146 mutants examined, 19 were found to have enzymes with reduced subunit association. These altered enzymes are especially sensitive to inactivation by urea which, at concentrations that do not affect the normal enzyme, causes dissociation into subunits. Mapping with overlapping deletions showed that the mutations affecting quaternary structure are not distributed continuously, but occur in five or six groups within the gene. The mapping indicates that polypeptide sequences involved in subunit association and in substrate binding are contiguous. A model for f:!-galactosidase structure is suggested in which substrate binding sites are provided by the clefts formed between subunits when they associate.
Characterization and Intragenic Position of Mutations in the Gene for Galactoside Permease of Escherichia coli
Authors: Langridge J
Published: July 2016

To test certain models for the structure of the gene for galactoside permease and its product, appropriate mutants of E. coli were isolated after mutagenic treatment, partially characterized and mapped. The 69 mutants found to be in the permease gene were mapped by crosses with episomal deletions which divided the gene into 13 regions.
Studies on the Carbohydrate of Egg-white Ovomucin
Authors: Smith MB , Reynolds TM , Buckingham CP , Back JF
Published: July 2016

Ovomucin, prepared from thick egg white by precipitation and washing with 12� 5 % (w/v) KH2P04 at pH 5� 0, was analysed for amino acids and carbohydrate, and found to vary in composition between different preparations. Glycopeptides were separated from Pronase digests of reduced ovomucin and fractionated by gel filtration into two classes which were markedly different in composition. Each class of glycopeptides accounted for about half of the total moles of carbohydrate residues in the original ovomucin.
The Chemical Composition of Wool. XII Further Studies on Cortical Cells and Macrofibrils
Authors: Kulkarni VG , Bradbury JH
Published: July 2016

Ultrasonication of Merino wool in formic acid liberates cuticle and then orthocortical cells. Further treatment produces a mixture of orthocortical and paracortical cells and finally a clean sample of paracortical cells is obtained.
Mutagenicity of DDT in Mice, Drosophila melanogaster and Neurospora crassa
Authors: M Clark Julian
Published: July 2016

The pesticide DDT was examined for possible mutagenicity in mice, D. melanogaster and N. crassa. Through the use of the dominant-lethal assay it was found that acute oral doses of DDT (2 x 150 mg/kg body weight) in male mice induced dominant lethal mutations in early spermatid and spermato-cyte stages. Chronic oral doses of DDT (2 x 100 mg/kg body weight per week for 10 weeks) in male mice caused a persistent increase in the number of dominant lethal mutations. Histological sections showed that chronic treatment of mice with DDT caused changes in seminiferous tubule morphology and degeneration of B-type spermatogonia. Acute treatment of mice with DDT caused an increase in spermatocyte chromosome breakage, stickiness and precocious separation of the X and Y bivalent.
Hydrogen?Deuterium Exchange in the Genetic Variants A, B and C of Bovine ß-Lactoglobulin
Authors: Ralston GB
Published: July 2016

The hydrogen-deuterium exchange in the p-Iactoglobulin genetic variants A, Band C was studied by using an infrared spectrophotometric technique. Between pD 3� 1 and 7� 6 the exchange behaviour of all three proteins was identical, within the limits of experimental accuracy. Conformation transitions that result in changes in specific optical rotation between pH 4 and 6 for each of the proteins could not be detected by means of the hydrogen exchange measurements, suggesting that this particular conformation change is either very small in terms of the numbers of peptide groups involved, or is limited to rapidly exchanging surface groups. In the pD range studied the exchange of all three proteins was consistent with the EX2 mechanism.
Effect of Composition of Tris-based Diluent on Survival of Boar Spermatozoa following Deep Freezing
Authors: Visser D , Salamon S
Published: July 2016

Six factorial experiments were conducted to examine the effects of concentrations of 2-amino-2-hydroxymethylpropane-l,3-diol (tris), sugars, erythritol, catalase, ethylenediaminetetra-acetic acid (EDTA), glycerol and egg yolk in the freezing diluent on the survival of boar spermatozoa after freeze-thawing.
Fertility after Surgical Insemination with Frozen Boar Semen
Authors: Salamon S , Visser D
Published: July 2016

Seventy-six sows and gilts exhibiting natural oestrus were surgically inseminated with semen initially diluted with yolk-tris-EDTA-glycerol diluent and frozen by the pellet method. The inseminations covered three experiments in which volume of inseminate, motile spermatozoa per dose and time of insemination in relation either to the onset of oestrus or to ovulation were examined.
Osmotic Effects of Sorbitol Accumulation in Monkey Kidney Epithelial Cell Cultures
Authors: Hutton JC , Schofield PJ , Williams F , Hollows FC
Published: July 2016

It has been observed that primary monolayer cell cultures derived from monkey kidney cortex behave in a similar manner to the mammalian lens in that they accumulate high concentrations of sorbitol when they are incubated in medium containing a high glucose concentration (33 mM). An investigation was undertaken to determine whether the accumulation of sorbitol by these cultures results in cellular damage by an osmotic mechanism similar to that which has been proposed to occur in the lens.
Studies on the Apoproteins of the Major Lipoprotein of the Yolk of Hen's Eggs I. Isolation and Properties of the Low-molecular-weight Apoproteins
Authors: Burley RW
Published: July 2016

In a continuing study of protein-lipid interactions in egg yolk, the total apoprotei.n mixture (i.e. the 'apovitellenins') from the high-lipid, low-density lipoprotein (density 0�97 gJml) of the yolk from hen's eggs has been isolated in a soluble form. By gel-filtration chromatography in 6M urea the mixture has been separated into several fractions from which three new low-molecular-weight proteins (I, la, and 11), making up about 30% of the total, have been isolated. The most plentiful of these (I) consists of stable aggregates with several identical subunits each of molecular weight about 10000. This protein is analogous to the principal protein from the corresponding lipoprotein of emu's egg yolk, i.e. emu's apovitellenin I. Hen's apovitellenin I has a slightly different amino acid composition from that of the emu; notably it contains a sulphydryl group. The hen's protein also forms more stable aggregates that are dissociated by detergent and by guanidine hydrochloride but are stable in urea.
Pole Cells of Drosophila paulistorum Embryologic Differentiation with Symbionts
Authors: Ehrman Lee , Daniels Stephen
Published: July 2016

The pole cells of young D. paulistorum embryos are destined to form the germinal cells of both male and female imagoes. In addition, specialized portions of the midgut may be derived from pole cell progenitors. In this initial study of their embryogenesis by means of electron microscopy, various stages of pole cell development are shown in both non-hybrid (potentially fertile) and intersemispecific hybrid (potentially sterile as males) materials. Originally, approximately 5 or 6 cells emerge to form the early polar cap and subsequently divide asynchronously until the 35-50 cells of the late polar cap are derived. Unlike other Drosophila species, however, mycoplasma-like symbionts, apparently an hereditary infection, have been traced to locations within the cytoplasm of these pole cells. They are depicted as arriving there after transmission via the egg cytoplasm, implicating this as their probable route of entry into the future germinal tissues of adult flies. It is postulated that these microorganisms function as an infectious reproductive isolating mechanism fostering hybrid male sterility between D. paulistorum semispecies.
Effects of Egg Yolk, Glycerol and the Freezing Rate on the Viability and Acrosomal Structures of Frozen Ram Spermatozoa
Authors: Watson PF , Martin ICA
Published: July 2016

The influence of egg yolk, glycerol and the freezing rate on the survival of ram spermatozoa and on the structure of their acrosomes after freezing was investigated. Egg yolk was shown to be beneficial not only during chilling but also during freezing; of the levels examined, 1� 5 % gave the greatest protection. Although the presence of glycerol in the diluent improved the survival of spermatozoa, increasing concentrations produced significant deterioration of the acrosomes. With closely controlled linear cooling rates, no overall difference was detected in the survival of spermatozoa frozen at rates between 6 and 24�C per min. However, a significant interaction between freezing rate and the inclusion of glycerol in the diluent showed that glycerol was less important at the highest freezing rate. A sudden cooling phase near to the freezing point following the release of the latent heat of fusion was not detrimental to spermatozoa.
Artificial Induction of Lactation in Cattle by Use of Dexamethasone Trimethylacetate
Authors: Fulkerson WJ , McDowell GH
Published: July 2016

Injections of dexamethasone trimethylacetate initiated lactation in nulliparous Ayrshire heifers previously given a series of injections of oestradiol benzoate plus progesterone to develop mammary glands. Essentially normal lactation occurred following injection of 20 mg/day dexamethasone for 3 days, whereas injection of 40 mg/day for 4 days initiated secretion of smaller volumes of milk-like fluid containing relatively high levels of lipid. Milking alone failed to initiate lactation.
A Comparison of the Uptake of [75Se] Selenite, [75Se] Selenomethionine and [35Se]Methionine by Tissues of Ewes and Lambs
Authors: N Fuss Christine , Godwin KO
Published: July 2016

The fate of selenium, given as Na275Se03, or [75Sejselenomethionine, and of [35Sjmethionine administered intravenously to ewes and lambs, has been examined. The main intention was to follow the incorporation of selenium into protein in a number of tissues, including liver and kidney, and to measure the extent of that incorporation of selenoamino acid, particularly with respect to the administration of selenite. The ewes chosen were lactating ewes with lambs at foot, and the lambs were animals which had been weaned on to fodder low in selenium and were recovering from white muscle disease with selenium therapy. These two experimental situations were chosen as they offered conditions under which selenium incorporation might be considered to be maximal.
Dependence upon Bile Volume of the Biliary Excretion of Bromocresol Green and Amaranth in the Anaesthetized Rat
Authors: G Clark Alan , M Rogers KarI
Published: July 2016

The kinetics of the biliary excretion of both bromocresol green and amaranth are better described in terms of rate equations that are functions of the cumulative volume of bile excreted rather than of time. The rate of disappearance of bromocresol green from the liver also appears to depend on the volume of bile excreted rather than on time. It is proposed that bromocresol green, and probably also amaranth, rapidly equilibrates between the hepatic and biliary compartments as a result of reabsorption from the biliary tree and that the rate-limiting factor in the biliary excretion of these dyes is the removal of dye from the biliary tree by bulk flow.
Effects of Intravenous Infusion of Mimosine on Wool Growth of Merino Sheep
Authors: Reis PJ
Published: July 2016

Merino sheep were given continuous intravenous infusions of L-mimosine for periods of It, 2 or 21 days; efficacy as a defleecing procedure and effects on subsequent wool growth were measured. In addition, the amino acids tyrosine, phenylalanine and cystine were investigated as antagonists to the effects of mimosine.
Renal Response to Intravenous Phosphate Infusion in the Sheep
Authors: Tomas FM
Published: July 2016

Renal clearance experiments were performed on six Merino ewes in which plasma phosphate concentrations were increased by the intravenous infusion of isohydric sodium phosphate. As the phosphate load to the kidney increased, the renal tubular reabsorptive capacity became saturated and a definite tubular maximum for phosphate reabsorption (Tmp) was demonstrated. The Tmp was directly related to the glomerular filtration rate and had a mean value of 333�1 � 27�0 (S.E.M.) /lmol! min or 416� 6� 13� 5/lmol!100 ml glomerular filtrate. Calcium infused concurrently with phosphate in order to maintain plasma total calcium levels did not alter the Tmp. Ultrafilterability of calcium and phosphate in the plasma decreased with phosphate infusion and this was accentuated by an accompanying calcium infusion.
Artificial Induction of Lactation in Ewes: The Relative Importance of Oxytocin and the Milking Stimulus
Authors: Fulkerson WJ , McDowell GH
Published: July 2016

Eight ovariectomized and four intact ewes were given oestrogen plus progesterone to develop the mammary glands. The intact ewes (group A) and four ovariectomized ewes (group B) then received four injections each day of 1 i.u. syntocinon for 5 days whereas the other four ovariectomized ewes (group C) received placebo injections of 0�9 % saline. Milking commenced the day after the last of these injections.
Cytogenetical Studies in Wheat VIII. Telocentric Mapping and Linkage Studies Involving Sr22 and other Genes in Chromosome 7AL
Authors: T The T , McIntosh RA
Published: July 2016

The gene Sr22 conditioning low reaction to Puecinia graminis tritid was located by telocentric mapping on chromosome 7 AL at 27 � 4 crossover units from the centromere. Sr22 was approximately 2 crossover units from en-AI (ehlorina) and 41 units from PmI for low reaction to Erysiphe graminis trifid; however, the order of Sr22 and en-AI relative to PmI was not resolved. Maximum recombination between PmI, Lr20 and SrI5, for low reactions to E. graminis tritici, P. reeondita and P. graminis tritid respectively, was estimated to be O' 3 crossover units at the 95 % probability level.
Some Effects of Pressure Treatment on Actomyosin Systems
Authors: O'Shea JM , Horgan DJ , JMacfarlane J
Published: July 2016

Natural actomyosin, actin and myosin, have been pressurized at up to 150 MN/m2 for 1 h at O�C and examined 3-5 h later. Pressurization of myosin resulted in the formation of aggregates with a molecular weight approximately that expected for a dimer, whereas with F-actin depolymerization occurred. With actomyosin, a gel to sol transition was promoted. Viscosity and light-scattering measurements indicated that pressurization results in a large measure of disaggregation of actomyosin in solution. Pressurization of actomyosin resulted in a greater decrease in the calcium-sensitive, than in the calcium-independent, Mg2+ ATPase activity. The Ca2+ and K+-EDTA ATPase activities of myosin were inhibited to about the same extent.
Glucose and Acetate Metabolism in Sheep at Rest and During Exercise
Authors: Judson GJ , H Filsell O , Jarrett IG
Published: July 2016

Total entry rate of blood glucose and the rate of irreversible loss of blood acetate and its oxidation have been examined in sheep at rest and while walking on a horizontal treadmill at 5 km/h for 2 h. Sheep were given their daily ration of 1000 g chaff in 24 equal portions at hourly intervals and received multiple intravenous injections of [2-3H]glucose and intravenous infusions of [1-14C]acetate and NaH14C03 ? At rest the total entry rate of blood glucose was 0�44 � 0�03 mmol/min (values given as mean � s.e.m. for four sheep), the glucose pool was 23 � 1 mmol and the rate of irreversible loss of blood acetate was 2�3 � 0�1 mmol/min. During exercise, the total entry rate of blood glucose was 0�84 � O� 04 mmol/min, the glucose pool was 27 � 2 mmol and the rate of irreversible loss of blood acetate was 2�6 � O� 1 mmol/min.
Studies With the Autotransplanted Ovine Pancreas: Glucagon and Insulin Secretion
Authors: Arcus AC , Jane Ellis M , Kirk RD , Beaven DW , Donald RA , Hart DS , Holland GW , Redekopp C
Published: July 2016

Basic studies on the secretion of glucagon and insulin by the ovine pancreatic autotransplant in the neck are described. Of the 17 transplants in the series none failed to secrete glucagon and only three failed to secrete insulin in detectable amounts. The longest surviving transplant actively secreted both hormones 3 years after transplantation and five other transplants were functional and the animals healthy after 16 months. Exocrine secretion disappears shortly after transplantation. Sodium butyrate and alanine each promoted the secretion of both hormones by the transplant. Glucagon failed to promote insulin secretion by the transplant, although it apparently stimulated the ovine in situ pancreas. The immediate (presumably direct) effect of insulin was to inhibit transplant glucagon secretion. Hypoglycaemia induced by peripheral insulin administration failed to stimulate glucagon secretion by the transplant, although it did promote glucagon secretion by the ovine in situ pancreas. Heparin did not markedly suppress basal transplant secretion of either glucagon or insulin.
Interacting Effects of Light and Temperature on Sporulation of Peronospora tabacina on Tobacco Leaves
Authors: Cohen YigaI
Published: July 2016

The interacting effects of light and temperature on spore formation of P. tabacina on tobacco leaves were investigated. The following points indicated that an enzymic build-up of an antisporulant during a wet light period and its enzymic decay over a dry dark period may explain the inhibitory effect of light upon sporulation, and its reversal by darkness. (1) Fluorescent blue light of relatively low photon flux density (3 �7 /lE m - 2 S -1) inhibited sporulation by 99 % at 20oe. (2) Light level and temperature during the sporulation period determined spore yield of the pathogen: at high temperatures (in the range 8-24�C) sporulation was inhibited at low light level, whilst no inhibition occurred at much higher light levels at low temperatures. (3) Preceding dry dark treatments given at 200e considerably diminished the inhibitory effect of light, but not if given at 100e. (4) The diffusion of an inhibitory compound from irradiated to unirradiated areas of detached leaves was demonstrated. (5) The continuing photosynthetic activity of the host in the light at 20oe, and the lack of sucrose following dark periods at lOoe, were not associated with the inhibitory effect of light. The similarity between the role of light in the present system and the role of light in activation and decay of phenylalanine ammonia-lyase is discussed.
Variations in the Spectrum of Desulfoviridin From Desulfovibrio gigas
Authors: Skyring GW , Jones HE
Published: July 2016

Desulfoviridin preparations from D. gigas showed variations in the position < of the absorption maximum (the p-peak) in the 580-nm region of the spectrum. On treatment with Na2S204 a preparation with a p-peak at 585 nm was affected rapidly, the 585-nm peak shifting to the 596-nm region; this was partially reversed by K3Fe(CN)6. Treatment of the original preparation with K3Fe(CN)6 resulted in a shift of the p-peak to 582-583 nm. Desulfoviridins with p-peaks from 580 to 583 nm were not rapidly affected by Na2S204. The spectrum of the chromophore of desulfoviridin was also affected by Na2S204 with the peak at 587 nm shifting to 597 nm; this effect was completely reversed by oxygen. There was no evidence to <show that spectral variations in desulfoviridin preparations were due to the loss or acquisition of metal ions during growth or to the selection of mutants containing spectrally different desulfoviridins. It is suggested that during biosynthesis or purification, desulfoviridin may be structurally modified, allowing partial detachment of the chromophore, thus causjng a change towards the spectral properites of the detached chromophore.
Polypeptides From Serum Low-Density Lipoproteins of Pigs (Sus Domesticus)
Authors: Walkley CS , Husbands DR
Published: July 2016

Low-density lipoproteins floating between densities 1� 006 and 1 . 063 g cm - 3 were isolated by centrifugation of blood serum obtained from 24-h fasted pigs (Sus domesticus). This lipoprotein fraction contained two components with SF 1 . 063 values of 3 . 4 and 2� 3 at 20DC when examined by analytical ultracentrifugation. Delipidation of the lipoprotein yielded 15 % recovery of soluble protein whereas succinylation of the lipoprotein prior to delipidation gave 95 % recovery of soluble protein. Chromatography on Sephadex Gl00 in 8 M urea of these delipidation products yielded three fractions of different sizes which were present in both native and succinylated apoproteins. These fractions from the succinylated apolipoproteins were further characterized. A polypeptide fraction comprising 70 % of the total protein had an apparent molecular weight of 34000 and contained greater amounts of amino acids with hydrophobic side chains than did the second fraction of apparent molecular weight 22000 which contained 15 % of the protein. The third fraction of apparent molecular weight 12 500 contained 15 % of the protein.
Hybrid Dysgenesis in Drosophila Melanogaster: A Possible Explanation in Terms of Spatial Organization of Chromosomes
Authors: Sved JA
Published: July 2016

Male.recombination and female sterility, two aspects of hybrid dysgenesis in D. melanogaster, have been studied in crosses between a locally collected wild population and laboratory strains. Dysgenesis occurs in the Fl hybrid of such crosses only if the wild type is used as maie parent and the laboratory strain as female, suggesting an interaction between genotype and cytoplasm. However the results from further crosses are difficult to interpret in terms of a conventional genotype--cytoplasm model, and suggest that for dysgenesis to occur it is necessary-that the wild-type chromosomes be contributed by the male parent. Furthermore, receipt of any of the three major wild-type chromosomes in crosses to laboratory females is sufficient to cause hybrid dysgenesis.
The Conformational Stabilities of Tropomyosins
Authors: Woods EF
Published: July 2016

The stability to denaturation by heat and guanidine hydrochloride of seven vertebrate (including skeletal, cardiac and smooth muscle) tropomyosins and three invertebrate tropomyosins was examined. The transition profiles were discontinuous and in many cases distinct plateaux were observed which indicated the presence of unique partially unfolded states at intermediate temperatures and guanidine hydrochloride concentrations. The denaturation by guanidine hydrochloride could be described in the majority of cases by a model in which the native state unfolds to a partially unfolded stable intermediate which then unfolds to the completely denatured state. On this basis it was possible to estimate the free energies of unfolding in water. It was shown that part of the IX-helical structure of tropomyosin is only marginally stable and the free energy of unfolding in water of this segment is less than values found for globular proteins, whereas another segment (or segments) has a stability comparable to that found for globular proteins. The stepwise unfolding may be explained in terms of the coiled-coil interactions in tropomyosin.
Colouring Matters of the Aphidoidea XLII. Purification and Properties of the Cyclising Enzyme [Protoaphin Dehydratase (Cyclising)] Concerned with Pigment Transformations in the Woolly Aphid Eriosoma lanigerum Hausmann (Hemiptera: Insecta)
Authors: Cameron DW , Sawyer WH , Trikojus VM
Published: July 2016

Dried extracts of woolly aphid were treated with n-butanol, then by chromatography on DEAESephadex A50 and finally by filtration on Sephadex G150 to yield a substantially homogeneous protein catalysing the conversion of the aglucone of protoaphin into xanthoaphin. Traces of lowmolecular- weight contaminants were removed by chromatography on Sephadex G 100. The enzyme, which has a molecular weight of 120000�2000 and a high content of p-structure, was inhibited by naphthoresorcinol. Its glycoprotein nature was indicated by amino acid analysis.