bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrastructure and Differentiation In Chara Sp. III. Formation of the Antheridium
Authors: Pickett-Heaps JD
Published: November 2018

The formation of the antheridium from an enlarged nodal cell is described. After a basal cell has been cut off, precisely oriented mitoses divide the antheridial cell initially into octants; then follow two periclinal divisions in each octant. The outer layer of cells become the shield cells, the middle form the manubria, and the inner capitula cells divide further to produce secondary capitula and ultimately the spermatogenous threads. The shield cells become compartmentalized during enlargement by ingrowths in the wall which finally form a very distinctive pattern. Microtubules are associated with the regions of wall deposition. Plastids in the shields accumulate large numbers of globuli, and this is probably associated with the orange pigmentation they acquire. Large amounts of material seem to be secreted into the antheridia by the manubria; this material is formed within large vesicles which are apparently discharged through the plasmalemma. In the young capitula, a characteristic, highly organized grouping of many cytoplasmic microtubules forms a band which appears to wind through the cytoplasm; its significance and functions are obscure. Presumptive "spherosomes" are present in large numbers in these and spermatogenous cells. The spherosomes and lipid-like inclusions are very frequently coated with membranes of the endoplasmic reticulum.
An Association Between Serum Amylase Phenotype and Tick Infestation in Cattle
Authors: Ashton GC , Seifert GW , Francis J
Published: November 2018

Twenty-five popUlations of cattle totalling 741 animals were analysed for serum amylase type. The number of ticks (Boophilus microplus) carried by these animals had been determined on various occasions prior to blood sampling. Tick burden was regressed on phenotype within populations and it was found that animals with the Am G phenotype carried significantly more ticks than other phenotypes.
Deep Freezing of Ram Semen: Recovery of Spermatozoa After Pelleting and Comparison With Other Methods of Freezing
Authors: Salamon S
Published: November 2018

Four factorial experiments were conducted in which were examined and compared factors which affect revival of ram spermatozoa after pellet.freezing and other methods of freezing. Revival of spermatozoa after pellet.freezing was the best in egg yolk-lactose (333 mM), followed by egg yolk-raffinose (333 mM), egg yolk-glucose (355 mM), and egg yolk-fructose (355 mM) diluents. Within the glycerol range of 0-7%, lactose gave the best results with 3%, raffinose and glucose with 5%, and fructose with 7% (vJv) glycerol.
The Chemical Composition of Wool V. The Epicuticle
Authors: King NLR , Bradbuby JH
Published: November 2018

The cuticle membranes of wool raised by chlorine (epicuticle) and by bromine have been isolated and their thicknesses determined by electron microscopy of gold-shadowed specimens. These were found to be 32�10 A and 140�40 A respectively. The epicuticle consists of 78% protein, 5% lipid, 4% ash, and a negligible amount of carbohydrate. Amino acid analyses of the epicuticle and the dissolved protein which fills the Allworden sacs show that (with the exception of glycine) those amino acids which are present in larger amount in the epicuticle than in the whole cuticle are present in smaller amount in the dissolved protein and vice versa. Furthermore, the amino acid composition of the epicuticle resembles that of the cuticle more closely than that of the protein from the cell membrane complex. This fact, together with its low lipid content, suggests that it may not originate from the cuticle cell membrane complex.
An Analysis of the Water Potential Isotherm in Plant Tissue
Authors: Noy-Meir I , Z Ginzburg B
Published: November 2018

The water potential isotherms of leaves of carob (a sclerophyllic xerophyte), plane tree (a mesophyte), and saltbush (a semisucculent xero-halophyte) were measured by vapour equilibration with filter paper. The isotherm of the living tissue was partitioned into components by measuring the isotherms of killed tissue and of isolated matrix fractions. Empirical functions were fitted by regression to each of the components. The isotherm of the matrix fractions fitted best to a function of the form 'P = -a/w2+b/w and the isotherms of killed tissue, whether before or after subtraction of the matrix, to a function of the form 'P = -a/w2-b/w. The first term indicates non-ideality of the tissue solution. The water potential difference between living and killed tissue, which is an approximation of the hydro-static potential, was far from linear with water content; either a quadratic function or two discontinuous linear ones could be fitted to it. Negative hydrostatic poten-tials were measured, the highest values (20 atm) being attained in carob. A hyster-etic component was measured both in the entire tissue and in the matrix fractions.
Effects of Water, Light, and Nutrition on Flower-Bud Initiation in Apricots
Authors: I Jackson D
Published: November 2018

Young apricot trees were grown under different levels of light, nutrition, and water. Both high nutrition and adequate water increased the production of nodes and their associated leaves but did not affect internode length. Flower�bud initiation at each node was increased by high nutrition but unaffected by water level. Light intensity did not affect the production of nodes and leaves but low light reduced flower� bud initiation at each node and promoted internode elongation. Flower�bud initiation probably depends on a supply of metabolites in excess of the requirements of shoots, fruits, and roots and this may be mediated by the hormone system of the plant.
The Uptake and Effects of Calcium and Phosphate on Maturity, Lignification, and Peroxidase Activity of Wheat Internodes
Authors: Parish RW , L Miller F
Published: November 2018

Wheat (cv. Gabo) was grown in a controlled environment and supplied with various levels of calcium and phosphate. Low levels of phosphate accelerated maturity irrespective of calcium concentrations, while high phosphate levels delayed maturity. The converse applied to calcium concentrations, and phosphate effects tended to dominate those of calcium. The maturity effects partly explain the lower lignin content of plants grown with high levels of phosphate observed by other workers.
Selection in Reference to Biological Groups
Authors: Griffing B
Published: November 2018

Index theory is applied to selection methods which use individuals or ran-domly associated groups of individuals as basic units of selection. An index is developed which combines "direct" and "associate" phenotypic values in such a way as to invariably ensure a maximum, non-negative change in the population mean. The theory is applicable to populations of groups in each of which individuals may interact in any arbitrary manner, whether such interaction be cooperative or competitive in nature.
Development of Dormant Blastocysts Induced by Oestrogen in the Ovariectomized Marsupial, Maoropus Eugenii
Authors: J Smith Meredith , Sharman GB
Published: November 2018

OvaribJtomized and intact tammars (M. Ilugllnii) were injected with oestrogen (oestradiol benzoate) for 3 days. Five developing blastocysts were recovered from six animals killed 7 days after first injection of a total of 150 p.g of oestrogen. Four developing blastocysts were recovered from nine animals killed 7 days after first injection of a total of 300 p.g of oestrogen. A single blastocyst, which had undergone some development, was recovered from one of seven intact animals which received 150 p.g of oestrogen. Fewer blastocysts were recovered from ovariectomized animals receiving 300 p.g of oestrogen, and from intact animals receiving 150 p.g of oestrogen, than were recovered from ovariectomized non.injected animals and from ovariectom-ized animals receiving 150 p.g of oestrogen.
Action of Dinitrophenyl Amino Acids on Skeletal Muscle Proteins
Authors: Burley RW , P Robertson Jean
Published: November 2018

Isotherms for the total absorption ofbis(2,4-dinitrophenyl)-L-lysine (bis-DNP-lysine) by rabbit skeletal muscle myosin and heavy meromyosin whose sulphydryl groups had been progressively blocked with p-chloromercuribenzoate were measured by equilibrium dialysis in Tris buffers containing potassium chloride.
Proteins of Keratin and their Synthesis
Authors: Fraser IEB
Published: November 2018

The presence within prekeratin cells of the wool follicle of both matrix and microfibrillar proteins analogous to proteins within keratinized tissue has been demonstrated.
Myooplasma-Like Bodies in Plants Affected by Legume Little Leaf, tomato Big Bud, and Lucerne Witches' Broom Diseases
Authors: Bowyer JW , Atherton JG , Teakle DS , A Ahern Gabrielle
Published: November 2018

Symptoms of plant disease which include stunting, proliferation of axillary shoots, general chlorosis, and sometimes greening and proliferation of floral parts have generally been ascribed to virus infection. Such diseases, collectively known as the "yellows group", include aster yellows (Smith 1957), lucerne witches' broom (Edwards 1935), and tomato big bud (Samuel, Bald, and Eardley 1933); They are not known to be sap-transmissible, but may be transmitted by dodder (Ouscuta spP"), by grafting, or by various leafhopper vectors (Kunkel 1952; Helms 1957; Smith 1957).
Effects of Vernalization, Photoperiod, and the Cotyledon on Flower Initiation in Greenfeast Peas
Authors: Amos JJ , Crowden RK
Published: November 2018

Estimates have been made of the quantitative contribution of each of the determinant factors, photoperiod, vernalization, and colysanthin (a presumed inhibitor of flower initiation formed in the cotyledon), in regulating flower initiation in the late-flowering pea cultivar Greenfeast.
Concomitant Photosynthesis Implicated in the Light Effect on Translocation in Bean Plants
Authors: Plaut Z , Reinhold Leonara
Published: November 2018

Light supplied during a 3-hr translocation period stimulated [14C]sucrose translocation in bean plants, both when the plants had spent the previous 30 hr in the light and when they had spent this period in the dark. Light during the trans-location period was also very effective when the latter was shortened to 30 min and followed a 30-hr pretreatment period in the light. It is thus unlikely that the light effect is due to a change in overall leaf sugar level, since the latter will not have altered markedly during the final 30 min of a light period of more than 30 hr. Not only was more 14C translocated out of the leaves in the light, but a far higher percentage of the 14C so translocated reached the roots.
The Utilization of Root Organic Compounds During the Regeneration of Lucerne
Authors: Hodgkinson KC
Published: November 2018

Organic compounds in the roots of lucerne, labelled with 14C following the assimilation of 14C02 by the shoots 1 day prior to complete herbage removal, were subsequently lost from the roots either through respiration or translocation into new shoots for about the first 20 days of regeneration. The majority of the compounds used in these two processes were derived from the tap-root. Autoradiography revealed that compounds labelled with 14C 10 days prior to herbage removal were translocated from the roots into the new shoots.
The Mechanism of Pathogenicity of Sirex Noctilio on Pinus Radiata II. Effects of S. Noctilio Mucus
Authors: Coutts MP
Published: November 2018

Effects on P. radiata of a mucus secretion from the female wood wasp are described. When injected into the sapwood, this substance induced the rapid physiological changes in the crown which are characteristic of trees attacked by S. noctilio. Among these was the accumulation of starch in the leaf and a decrease of starch in the bark of the stem implying that the translocation of photosynthate was inhibited. This was followed by premature senescence and abscission of much of the foliage and increased susceptibility to the fungus, Amylostereum sp., which occurs in symbiosis with the insect. Therefore it is concluded that the mucus secretion conditions the tree, which is subsequently killed by the fungus.
The Possibility of Common Amino Acid Sequences in High-Sulphur Protein Fractions from Wool
Authors: Darskus RL , Gillespie JM , Lindley H
Published: November 2018

S-Carboxymethyl derivatives of the high-sulphur components of reduced Merino wool have been subdivided by chromatography into 17 fractions, the amino acid compositions of which are reported. Tryptic, chymotryptic, and thermolysin digests of each fraction have been studied by high-voltage paper electrophoresis at pH 3�5 and 6�5. The results suggest that the high-sulphur proteins consist of families of proteins probably containing common structural features. Evidence is presented that the heterogeneity of high-sulphur proteins is not artefactual.
Environmentally Induced Variability in the Host Reaction of Barley to Net Blotch
Authors: Khan TN , Boyd WJR
Published: November 2018

The host reaction of two Ethiopian and four Manchurian resistant varieties, and one susceptible variety of barley to isolate 177 of Drechslera teres was studied under a range of environmental conditions. The effects were specific to the variety(ies) used, with the exception of the factor of post-inoculation temperature. High post-inoculation temperatures brought about the breakdown of resistance in all the varieties.
Ion Absorption in Atriplex Leaf Tissue III. Site of Metabolic Control of Light-Dependent Chloride Secretion to Epidermal Bladders
Authors: Lüttge U , Osmond CB
Published: November 2018

The nature and location of the light-stimulated active transport of chloride to the epidermal bladders of A. 8pongio8a leaves was examined. Chloride transport to the bladder vacuole was found to have properties similar to those for light-dependent
The Influence of Sulphur-Containing Amino Acids on the Biosynthesis of High-Sulphur Wool Proteins
Authors: Broad Andrea , Gillespie JM , Reis PJ
Published: November 2018

The sulphur content of wool can vary within the range of about 2·7-4·2%
depending on the diet of the sheep. The lower limit may represent a limiting
fundamental structure for wool as it has not been possible to produce wool of sulphur
content lower than 2·7% during sulphur-deprivation experiments. There is a highly
significant linear relationship between the sulphur content of wool and its content of
high-sulphur proteins. The major part of this variation in sulphur content is due to
alterations in the extent of biosynthesis of proteins of extremely high sulphur content
having about one-third of the amino acid residues presen1, as half cystine. The
biosynthesis of these proteins may be under separate metabolic control for they can be
produced at maximum rate under conditions where the synthesis of other highsulphur
proteins is partly inhibited by a sulphur-deficient diet or by high levels of
DL-methionine supplementation
An Analysis of Growth Processes in Cattle Coats and their Relations to Coat Type and Body Weight Gain
Authors: Turner HG , Schleger AV
Published: November 2018

Hair regrown on a clipped patch of skin during each of nine intervals covering
a period of 13 months was sampled, counted, and measured. Methods of estimating
the rate of appearance of new hairs, the proportion of follicles with growing hairs, the
duration of growing and resting phases of follicles, and linear growth rate of hairs are
described. Results obtained from 70 animals are presented. Seasonal changes in the
various parameters, and their roles in producing seasonal changes in coat type, are
analysed and discussed. Replacement of hairs occurred continuously and amounted
to slightly more than two hairs per follicle per year; rates of replacement were highest
in spring and in summer. The number of growing hairs and the time for which each
hair grew were much lower in summer than in autumn.
Effects of Oxygen and Carbon Dioxide on Respiration, Storage Life, and Organic Acids of Green Bananas
Authors: Mcglasson WB , Wills RBH
Published: November 2018

Green bananas were held in humidified gas streams comprising air (control); "high carbon dioxide" (A) (5% CO2, 20% O2,75% N2); "low oxygen" (B) (0% CO2, 3%,02,97% N2); "high carbon dioxide-low oxygen" (C) (5% CO2, 3% O2, 92% N2). Ripening in A, B, and C was delayed at least 2, 8, and 12 times respectively compared with air. These three gas streams also reduced the rates of oxygen uptake by the fruit but increased the total oxygen uptake over the period before the beginning of the respiratory climacteric.
Inhibitor Studies on the Biosynthesis of Chondromucoprotein by Chicken Embryonic Cartilage
Authors: Jeffrey PL , Rienits KG
Published: November 2018

Using chick embryonic cartilage, the effects of puromycin, ribonuclease, and chloramphenicol on the incorporation into chondromucoprotein of radioactively labelled leucine, glucose, and inorganic sulphate have been studied.
Ethanolamine Phospholipid Metabolism in Myelinating Rat Brain
Authors: Wysocki SJ , Segal W
Published: November 2018

3H-1abelled ethanolamine phospholipids were isolated from the brains of 13-day-old rats after intracerebral injection of [9,1O-3H]palmitic acid. Groups of rats of the same age were injected intracerebrally with preparations derived from the whole labelled fraction, the ethanolamine plasmalogen-depleted fraction, or [14C]palmitic acid. A study of the distribution of radioactivity in phospholipids and sphingolipids, 2 hr after injection, indicates that the alkenyl chains of ethanolamine plasmalogen are effective precursors of the acyl groups of sphingomyelin and cere-broside. This role of plasmalogen is discussed in terms of the properties and distribu-tion of plasmalogenase, aldehyde dehydrogenase, and fatty acid chain-lengthening enzymes in brain.
Keratin Fibres VI. Mechanism of the Allwörden Reaction
Authors: Bradbury JH , Leeder JD
Published: November 2018

On treatment with chlorine water, Allworden sacs are formed on the surface of keratin fibres and on single cuticle cells separated from fibres. Their rate of formation has been studied for wool fibres subjected to various pretreatments. The experimental results can be explained in terms of six conditions, all of which must be satisfied if Allworden sacs are to be formed.
The Significance of Hormones, Bile Salts, and Feeding in the Regulation of Bile and Other Digestive Secretions in the Rat
Authors: Shaw HM , Heath T
Published: November 2018

Conscious rats produced bile at 19 � 0�6 fLl/kg/min during periods of bile deprivation. When sodium taurocholate was infused intravenously, the bile flow increased to 54 � 4� 8 fLl/kg/min-a value almost identical to that recorded in other rats during normal recirculation of endogenous bile salts.
Photosynthesis by Thin Leaf Slices in Solution II. Osmotic Stress and Its Effects on Photosynthesis
Authors: Jones HG
Published: November 2018

The effects of osmotic stresses on photosynthetic 14C02 fixation by cotton leaf slices were investigated. Using mannitol and sodium chloride as examples of osmotica which entered leaf cells fairly slowly, and ethylene glycol as a rapidly permeating osmoticum, the relative importance of different components of tissue water status in inhibiting carbon fixation was studied.
A Study of the Interaction of Cold Stress, Age, and Phosphorus Nutrition on the Development of Lotononis Bainesii Baker
Authors: Gates CT , Haydock KP , Williams WT
Published: November 2018

The effects that specific amounts of cold stress had on the development of the tropical legume L. bainesii were assessed for plants of four ages grown in a nitrogendeficient soil. They were dependent primarily upon symbiotically fixed nitrogen, when receiving phosphorus at five treatment levels. The plants received normal lighting and a 12-hr day length under controlled environment, and the cold stress was gradually increased from nil to frosting.
The Effect of Actinomycin D on The Binding of Tritiated Oestradiol by the Vagina of the Ovariectomized Mouse
Authors: Stone GM , Pollard Irina
Published: November 2018

The binding of [3H]oestradiol-17 f3 by whole mouse vaginal tissue in vivo, and by subcellular fractions of mouse vaginal homogenates in vivo and in vitro, was examined at varying times after an intravaginal injection of the antimetabolite, actinomycin D.
Changes in Distribution of Alkaline Phosphatase During Early Implantation and Development of the Mouse
Authors: Smith MSR
Published: November 2018

Changes in the uterus of the mouse during the oestrous cycle and early development from 90 to 190 hr post coitum were examined to demonstrate variations in the occurrence of alkaline phosphatase (ALP) activity.
Deep Freezing of Boar Semen II. Effects of Method of Dilution, Glycerol Concentration, and Time of Semen-Glycerol Contact on Survival of Spermatozoa
Authors: Wilmut I , Salamon S , Polge C
Published: November 2018

Five factorial experiments were conducted to examine the effects of glycerol concentration and processing procedures prior to freezing on the revival of boar spermatozoa upon thawing.
Development of Photosynthetic Induction Transients in Greening Leaves of Wheat and French Bean
Authors: Kirk JTO
Published: November 2018

The induction phenomena of photosynthesis at different stages during the greening of dark-grown wheat and bean leaves have been studied. When etiolated wheat leaves first acquire photosynthetic activity, the characteristic time course of oxygen evolution consists of a distinct lag phase followed by a slow rise to the steady state.
Effects of Genotype and Nutrition before Mating on the Reproductive Performance of Mice
Authors: Wodzicka-Tomaszewska Manika , Stephenson SK , Truscott TG
Published: November 2018

The effects of genotype and nutritional restriction before mating were studied in three lines of mice designated high (HL), control (CL) and low (LL). The HL and LL lines had been selected for differential body size and limb length relationships. This selection resulted in HL mice being larger and having relatively longer limb bones than the randomly bred control line, while the converse was true of LL mice.
Effect of Protein and Energy Content of the Diet on the Rate of Sperm Production in Rams
Authors: Braden AWH , Turnbull KE , Mattner PE , Moule GR
Published: November 2018

In the first experiment, the effects of two levels of dietary protein and energy on the number of sperm
in the excurrent ducts, on the weight of the testes and on the weight of the seminal vesicles were
examined in two-year-old Merino rams from two Peppin and two non-Peppin strains. There were
large effects of diet on each of the three characters, the effect of energy intake being much greater than
that of protein intake. In addition, there were significant differences between strains: Peppin strain
rams had higher sperm numbers and testicular weights than non-Peppin strain rams, even though
liveweights were similar.
Two-trait Selection and the Genetic Correlation I. Prediction of Responses in Single-trait and in Two-trait Selection
Authors: Sheridan AK , Barker JSF
Published: November 2018

Selection using independent culling levels (20% overall selection intensity) was done for the four combinations of high or low third coxal bristle number with high or low sternopleural bristle number in Drosophila melanogaster. Single-trait lines from the base population were selected at 20 % selection intensity for 10 generations for high or low bristle number. Realized heritabilities and genetic correlations were estimated after 10 and 22 generations of selection in the two-trait lines, and also from the single-trait lines. There was considerable variation among replicate lines within treatments in selection responses, and in realized heritabilities and genetic correlations. Although average estimates of the realized parameters were all less than those made from a diallel analysis of the base population, the average base population genetic correlation and the average realized genetic corre-lations from single-trait and two-trait selection lines were reasonably similar. Predicted selection responses in both single-trait and two-trait lines using genetic parameters derived from a diallel analysis of the base population were greater than average realized responses. However, predicted selection responses in the two-trait lines using realized genetic parameters from the single-trait lines were in reasonable agreement with average realized responses.
The Influence of Cage Bedding on the Metabolism of Sulphobromophthalein Sodium by an Hepatic Cytosol-Located Enzyme System
Authors: Whelan G
Published: November 2018

The use of cage bedding prepared from pinewood shavings has been shown to be associated with an increase in the activity of sulphobromophthalein sodium (BSP) S-aryltransferase in the hepatic cytosol in rats housed on this substance. This increase was associated with enhanced secretion rates of dye into the bile due to an elevation in the biliary excretion rate of conjugated BSP. Analysis of the hepatic dye content at the time of maximal excretion of BSP into the bile indicated that this phenomenon was due to increased intrahepatic conjugation of BSP. This observation emphasizes the importance of considering environmental factors that may influence results when designing experiments on hepatic metabolism.
Changes in the Jugular Haematocrit of Sheep During Feeding
Authors: Dooleya PC , Williamsa VJ
Published: November 2018

Intact and splenectomized sheep with and without a rumen fistula were used to investigate changes in the jugular blood haematocrit and plasma osmolality during hourly and once-daily feeding regimes. Osmolality was also estimated in the ruminal fluid of fistulated sheep with spleens.
High-Sulphur Proteins From a-Keratins ll. Isolation and Partial Characterization of Purified Components From Mouse Hair
Authors: C Marshall Robert , Gillespie JM
Published: November 2018

The present paper continues the study of the reduced and S-carboxymethylated high-sulphur proteins from mouse hair. Fractions have been obtained in a substantially purified form by fractional precipitation with ammonium sulphate at pH 6, followed by ion exchange chromatography on cellulose phosphate at pH 2�6. Approximately 80% by weight of the high-sulphur proteins fall into the ultra-high-sulphur category (carboxymethyicysteine content greater than 26 residues per 100 residues), and they cover a molecular weight range of 17000-28000. The components show a remarkable diversity in amino acid composition; for example the contents of arginine and glycine each vary by about 3 : 1. The remainder of the proteins contain 17-20 residues per 100 residues of carboxymethyicysteine, are smaller in size (molecular weight 11 500), and also show great diversity in overall amino acid composition.
Preliminary Studies on the Mucus Secretion of the Wood Wasp, Sirex Noctilio F. I. Physicochemical and Biochemical Properties
Authors: Wong LK , Crowden RK
Published: November 2018

The major component of S. noctilio mucus appears to be a protein-polysaccharide complex with probable molecular weight in the range 60000-100000. In aqueous solution the macromolecule undergoes slow spontaneous disaggregation to yield dialysable subunits of molecular weight 2000-6000 which retain all the physiological activity of the whole mucus. More rapid disaggregation is brought about by treatment of solutions with moderate concentrations of NaC!, KCI or CaCI2 , or by heating. The native mucus contains amylase, esterase, phenoloxidase and proteolytic enzyme activities, and it is suggested that these enzymes may be responsible, at least in part, for the 'natural' disaggregation process.
Production of Endogenous Acetate by the Liver in Lactating Ewes
Authors: D Costa N , Mclntosh GH , Snoswell AM
Published: November 2018

The production of endogenous acetate by the liver has been investigated in lactating ewes using animals with indwelling arterial, and portal and hepatic venous cannulae. The capacity of the liver to produce acetate from acetyl-CoA in vitro has also been examined using homogenates prepared from liver biopsy samples. Mean arterial, portal and hepatic venous blood acetate concentrations in four ewes at 4 weeks lactation were 0'40, 1�00 and 1�46 mM respectively. The mean exogenous and endogenous acetate production rates were 56 and 54 mmol/h respectively, giving a total of 110 mrnol/h. The mean portal-hepatic venous difference in free fatty acid concentration was 81 11M. Converting this uptake of free fatty acids by the liver (based on palmitate as a standard) to 2-carbon equivalents, the acetate produced accounted for 70 % of the fatty acids taken up. The correlation coefficient (r2) between uptake of free fatty acids and production of acetate by the liver was o� 83 (P < O� 01),
The Chemical Composition of Wool XV. The Cell Membrane Complex
Authors: Peters DE , Bradbury JH
Published: November 2018

The cell membrane complex of wool has been examined by electron microscopy of stained. cross sections after immersion of the wool in formic acid. The cell membrane complex of the cortex is considerably modified by the treatment, but that of the cuticle appears unchanged. Resistant membranes from cuticle cells, cortical cells and wool have been prepared by treatment with performic acid-ammonia. Amino acid analyses show that the resistant membranes from the cuticle contain citrulline but those from cortical cells do not. It is concluded that the cell membrane complex of the cuticle differs from that of the cortex. Because of the high lysine content of the resistant membranes, their resistance to chemical attack, the hydrophobicity of epicuticle and the observation of a small amount of e-(y-glutamyl)lysine, it is postulated that the resistant membranes may contain an appreciable amount of e-(y-glutamyl)lysine cross links.
Solid-Phase Assay for Luteinizing Hormone in Mouse Plasma
Authors: Gidley-Baird AA , Bindon BM
Published: November 2018

A solid-phase tube assay for measuring LH levels in mouse plasma is described. The assay utilizes an antiserum to ovine LH and ovine LH standards and it measures LH levels in 20 III of plasma with a sensitivity of less than 0�6 ng/m!. Various parameters affecting the sensitivity and specificity of the assay were investigated. Serial dilutions of plasma from pregnant mice, a pituitary homogenate from mice and plasma from hypophysectomized mice, injected subcutaneously with ovine LB, ran parallel with ovine LH standards in plasma from hypophysectomized mice and plasma with low LH levels from intact mice. Ovine TSH showed about 12 % cross reaction in the assay system, whilst rat FSH and prolactin and also ovine FSH, prolactin and GH showed practically no cross reaction. Measurements of plasma LH levels have been made in hypophysectomized mice after injection with different vehicles containing 10 or 50llg LH or 50llg FSH per animal. Daily measurements of LH levels throughout pregnancy in the mouse show a rise in LH level prior to implantation and a further rise around mid-pregnancy which drops off sharply to levels which remain fairly constant until parturition when there is another rise.
Developmental Origin of Even Spacing Between the Microchaetes of Drosophila Melanogaster
Authors: Claxton JH
Published: November 2018

In D. melanogaster, evenness of spacing is a prominent feature of the patterns of microchaetes. As a general explanation of this characteristic, Wigglesworth has suggested a scheme whereby some epidermal cells become singled out (determined) at random to differentiate bristles, and the same potential in neighbouring cells is suppressed by the determined ones. Though this model may be satisfactory for other epidermal regions, the spacing between bristles within some of the mid-dorsal thoracic acrostic hal rows is too even to be accommodated.
Association of a Bacterium-Like Organism With Rugose Leaf Curl Disease of Clovers
Authors: Behncken GM , Gowanlock DH
Published: November 2018

White and crimson clover plants affected by rugose leaf curl disease showed temporary remission of symptoms when treated with weekly doses of penicillin applied as a soil drench. A small bacterium or bacterium-like organism was consistently associated with diseased plants of red, white and crimson clover and Trifolium semipilosum when sections of diseased tissues were examined by thin-section electron microscopy. No similar bacterial bodies were seen in sections cut from healthy plants. The bacterial bodies were restricted to phloem sieve tubes and phloem parenchyma cells and were irregularly distributed along vascular bundles within infected tissue. Infected phloem cells also contained electron-dense droplet material not seen in adjacent cells. The bacterial bodies associated with rugose leaf curl measured approximately 0�25.um in diameter and were 1-2.um in length, although more elongated bodies also occurred. The organism was bounded by a cell wall and plasma membrane, or a double membrane, both trilaminar in structure and separated by a lightly stained intermediate layer. The cell wall or outer membrane was darker-stained than the inner membrane and was undulating in outline. Although this organism has not yet been isolated in pure culture, the sensitivity of the pathogen to penicillin suggests that the bacterium-like organism seen by electron microscopy is the causal agent of rugose leaf curl disease.
Effect of Dimethyl Sulphoxide on the Expression of Nitrogen Fixation in Bacteria
Authors: L Skotnicki Mary , G Rolfe Barry
Published: November 2018

Storage in dimethyl sulphoxide (DMSO) of Escherichia coli K12 hybrids carrying nif+ genes from Klebsiella pneumoniae can result in selection of a defective nitrogen-fixing phenotype. Similar results are obtained with E. coli K12 hybrids containing the nitrogep-fixing capacity from Rhizobium trifolii. DMSO appears to affect particular inner membrane proteins associated with energy metabolism in E. coli K12 and four chromosomal regions (chID, chlG, his and unc) are associated with resistance to DMSO.
Metabolism and Defluorination of Fluoroacetate in the Brush-Tailed Possum (Trichosurus Vulpecula)
Authors: Mead RJ , Oliver AJ , King DR
Published: November 2018

The brush-tailed possum (T. vulpecula) from Western Australia was found to be nearly 150 times more resistant to fiuoroacetate intoxication in vivo than the same species from South Australia. Acetone powder preparations from the liver of animals from both populations showed similar abilities to convert fiuoroacetate into fiuorocitrate. Aconitate hydratase activity in liver preparations from both Western Australian and South Australian animals was similarly and competitively inhibited by fiuorocitrate. Both animals were capable of defiuorinating fiuoroacetate at similar rates by a glutathione-dependent enzymic mechanism resulting in the formation of free fiuoride ion and S-carboxymethylcysteine. Glutathione was also capable of partial protection against the toxic effects of fiuoroacetate in vitro by a further unelucidated mechanism.
The Goitrogen 3-Hydroxy-4(1H)-Pyridone, a RuminaI Metabolite From Leucaena Leucocephala: Effects in Mice and Rats
Authors: Hegarty MP , Phong Lee Chew , Christie GS , Court RD , Haydock KP
Published: November 2018

Mice fed a diet containing 1 % (w/w) 3-hydroxy-4(IH)-pyridone (DHP) developed goitre even with a diet high in iodine whereas mimosine (0�5% w/w) did not produce goitre even with a low-iodine diet. Thyroid enlargement was apparent (measured morphometrically) by the 7th week and was advanced by the 11 th week. Histologically the goitre was hyperplastic in type. No marked histological changes were found in other organs of mice fed DHP or any organs of mice fed mimosine, except for soine atrophy of hair follicles.
Sulfur and Methionine Metabolism in Sheep. I. First Approximations of Sulfur Pools in and Sulfur Flows From the Reticulo-Rumen
Authors: Doyle PT , Moir RJ
Published: November 2018

Sulfur pools in the rumen and sulfur flows from the rumen were investigated in two experiments with sheep on a diet containing equal parts of oaten and lucerne chaffs. The diet was fed at two levels, either chopped or pelleted, and with intraruminal DL-methionine supplements. Ruminal fluid volumes and fluid flows to the omasum were measured.
Factors Affecting the Viability of Frozen Stored Cattle Embryos
Authors: Bilton RJ , Moore NW
Published: November 2018

Cattle morulae and blastocysts were frozen, stored in liquid N2 and then warmed and cultured in vitro at 37� 5�C. They were frozen and stored in Dulbecco phosphate buffer enriched with 25 % cattle serum (DB+S)and containing 1�5 M dimethylsulphoxide (DMSO) or 1�0 M glycerol. Embryos were cooled at rates of 0 �13, 0 �15 or O� 30�Cjmin and warmed at rates of 1 �2, 2�2 or 4� 6�C/min (measured over the range 0 to - 50�C). Warming and cooling between 0 and 37� 5�C was at a rate of 0�7�C/min and, after warming, embryos were cultured in DB+S for 12-18 h. A number of embryos were transferred after culture to recipient cows.
Prostaglandin F2a-Induced Prolactin Release and Luteolysis in the Goat
Authors: McMahon GR , Shearman RP , Shutt DA , D Smith I
Published: November 2018

Injection of prostaglandin F2? (PGF2 .) initiated a significant increase in plasma prolactin levels in all goats except those in anoestrus. Luteolysis occurred in non-pregnant goats during the mid luteal phase when the goats were given PGF2? either with Or without the suppression of prolactin release by bromocryptine (CB154). Luteolysis and subsequent parturition also occurred in pregnant goats in mid and late gestation after PGF2? injection, with an associated release of prolactin and decrease in plasma progesterone. Acute prolactin release in response to injection of thyrotrophin releasing factor may have had a transient effect on plasma progesterone levels, but did not appear to be luteolytic in either pregnant or non-pregnant goats.
Genetics of Resistance to Tetraethyllead
Authors: Nassar R
Published: November 2018

A Drosophila melanogaster population was exposed for 25 generations to 60 pg tetraethyllead per gram of medium. Selection over this period resulted in an increase in fecundity, hatchability and larva-to-adult viability. Chromosome assay showed that response in these traits was generally under additive genetic control in conformity with existing results in the literature on the genetics of resistance to acute environmental stress in D. melanogaster.
Effect of Post-Mortem Electrical Stimulation on Ovine Sarcoplasmic Reticulum Vesicies
Authors: Tume RK
Published: November 2018

Sarcoplasmic reticulum (SR) vesicles from ovine skeletal muscle were iodinated with the use of immobilized lactoperoxidase to determine the location of proteins in the membrane and to observe any changes resulting from post-mortem electrical stimulation. The labelling pattern of the nonstimulated SR preparations was essentially the same as that observed previously for white muscle SR of rabbit. Most of the membrane proteins were labelled, except for the high-affinity calciumbinding protein. Electrical stimulation, however, resulted in an increased labelling of calsequestrin suggesting that this protein is more exposed as a result of such treatment. Certain activities of the adenosinetriphosphatase were affected by electrical stimulation. Both the steady-state concentration of phosphoenzyme and the ATP~PI exchange reaction were significantly reduced by electrical stimulation. It is not known if this alteration in the membrane is responsible for the reduced activity of the SR and thus the greater rate of post-mortem pH fall in electrically stimulated muscle. [Other keywords: Membrane phosphorylation, muscle pH, cold-shortening.]
Selection at the Acid Phosphatase Locus in Drosophila Melanogaster
Authors: Nassar R
Published: November 2018

Results of fitness estimates at the acid phosphatase locus in D. melanogaster revealed that the observed gene frequency equilibrium at the locus was maintained by frequency-dependent selection. Selection was due mostly to larva-adult viability. Gene-frequency response on media with substrate (IX-naphthyl acid phosphate) added may have been caused in part by selection at the acid phosphatase locus, although the possibility of a correlated response cannot be excluded.
Use of Cibracon Blue-Sepharose 6B to Detect Modifications of the Non-allosteric 6-Phosphofructokinase from Escherichia Coli K-12
Authors: N Ewings Ken , W Doelle Horst
Published: November 2018

In crude cell-free extracts of aerobically grown E. coli K-12, the non-allosteric form of 6-phosphofructokinase has a tetrameric molecular weight of 140000 with a low affinity � 5%) for the blue dextran chromophore-Cibracon Blue. The allosteric form has the same tetrameric molecular weight, but possesses a strong affinity for the blue dextran chromophore.
Some Physicochemical Properties of Erysimum Latent Virus
Authors: H Gough Keith , G Lilley Glenn , D Shukla Dharma , Woods Frank
Published: November 2018

Sedimentation velocity, diffusion coefficient and sedimentation equilibrium measurements gave a molecular weight of 5 �90 x 106 for the intact Erysimum latent virus. The molecular weight of the empty shell was estimated to be 3�92 X 106 and the protein subunit to be 21 600. The RNA content calculated from the molecular weights of the full and empty particles is 33 %, in agreement with that estimated from the buoyant density in caesium chloride. However, a direct phosphorus determination gave an RNA content of only 28 %.
Conversion of a Lipoprotein from Egg Yolk into a Membranous Form in the Presence of Yolk Lipid
Authors: Burley RW , Sleigh RW , M Bain Joan
Published: November 2018

Treatment of the major lipoprotein (density O� 95 gjml) from hen's egg yolk with aqueous dispersions of yolk lipid resulted in a mixture that contained new large globular particles with membranous outer layers. These particles, referred to as 'membranous globules', had diameters in the range 50-200 nm when viewed in the electron microscope and in appearance, properties, and composition resembled the 'insoluble yolk globules' that are a natural part of whole yolk
Effects of Selection on the Evolution of the Sex Ratio
Authors: Colgan DJ
Published: November 2018

Hypotheses as to the biological bases of observed sex ratios must explain the departures found in natural populations from the ratio which might be expected from the mechanism of sex determination in the species. Models based on the concept of parental investment (Fisher 1930) have been used to explain such departures but do not predict equilibrium sex ratios when viability selection discriminates between the sexes in the period between the end of parental investment and the maturity of the offspring.
Role of Microorganisms in the Metabolism of Termites
Authors: O’Brien RW , Slaytor M
Published: November 2018

This article reviews the current knowledge of the role of symbiotic microorganisms in the metabolism of termites. The symbiotic microorganisms, comprising bacteria (higher and lower termites) and protozoa (lower termites) are in the hindgut. Cellulose digestion in higher termites appears to be mediated solely by cellulolytic enzymes secreted by the termites. In the lower termites, cellulose is digested by enzymes secreted both by the termites and by the protozoa. The end products of protozoal metabolism (acetate and butyrate) are thought to be used by termites as energy sources. Another method of cellulose digestion is that of the Macrotermitinae which have a symbiotic relationship with fungi of the genus Termitomyces. The termites acquire cellulase from the fungus. The bacteria found in the hindgut are usually facultative even though the hindgut is anaerobic. Some of these bacteria appear to be involved in dinitrogen-fixation in the gut, but do not play any part in cellulose metabolism. Some evidence suggests that termites may be able to re-utilize the nitrogen in the uric acid stores in their fat body using hindgut bacteria. While there is evidence that lignin can be degraded in termite tissues it is difficult to assess the role of the hindgut micro biota in this process.
Nutrition of the Ewe and Embryo Growth during Early Pregnancy
Authors: Parr RA , Williams AH
Published: November 2018

Mature Merino ewes (n = 228) were fed rations at levels of either 5, 10, 15, 20, 30 or 40 g/kg daily from day 1 until day 35 after mating. Embryos were then removed from single ovulating ewes and, after being weighed and measured, were dissected and embryo liver weights were obtained. Plasma samples were taken from all ewes on days 5, 10, 15, 20, 27 and 35 after mating and later analysed for glucose concentrations.
Deep Freezing of Angora Goat Semen: Effects of Diluent Composition and Method and Rate of Dilution on Survival of Spermatozoa
Authors: Salamon S , Ritar AJ
Published: November 2018

Five factorial experiments were conducted to examine the effects of concentration of tris(hydroxymethyl) aminomethane (Tris), type and concentration of sugar in the diluent, rate and method of dilution on the survival of goat spermatozoa after freezing by the pellet method.
Serological Identification of Pilus Antigen and Other Protein Antigens of Bacteroides nodosus Using Electro-Blot Radioimmunoassay after Electrophoretic Fractionation of the Proteins on Sodium Dodecyl Sulfate Polyacrylamide Gels
Authors: O' Donnell IJ , Stewart DJ , Clark BL
Published: November 2018

Proteins of various strains of B. nodosus were fractionated by polyacrylamide gel electrophoresis in buffer containing sodium dodecyl sulfate. Transfer of these proteins to activated paper was carried out electrophoreticaIly (Electro-Blot). Subsequent sequential reaction of these proteins with sera from sheep which had been naturally infected with a particular strain of B. nodosus showed that there were antibodies to many (10-15) components. Antibodies to pilus proteins could be recognized but the most predominant antibody in natural infections was to antigens in the region of molecular weight approximately 75000. Assessment of the paper-bound antigens by successive reactions with antisera from sheep infected with other strains of B. nodosus gave a semiquantitative picture of cross-reactions.
Progesterone-regulated Changes in Oestradiol-stimulated Guinea Pig Uterus: Steroid Hormone Receptor Levels and RNA and Protein Metabolism
Authors: Stone GM , McCaffery C , Tassell R , Miller BG
Published: November 2018

By 24 h after its administration progesterone (P) is markedly anti-uterotrophic in the oestradiol (E2)-stimulated uterus of several species, including the mouse, but less so in the E2 -stimulated uterus of the guinea pig. The time course of some early responses to a single injection of P in the E2-stimulated uterus has been further examined in the guinea pig. E2 caused early, marked increases in uterine wet weight and in vitro rates of protein and RNA synthesis, which were maximal at 4 h, but relatively little tissue growth or increase in RNA: DNA and protein: DNA ratios at 12-24 h. P uniformly abolished all of these various uterine responses to E2.
Immunohistochemical Demonstration of Somatostatin in the Pancreas of Fetal and Adult Sheep
Authors: Reddy S , Oliver JR , Elliott RB
Published: November 2018

Pancreatic cells immunoreactive with rabbit anti-somatostatin serum were demonstrated in fetal and adult sheep by immunofluorescence histochemistry. Our observations provide evidence that in the sheep the pancreas is a major site of production of the hormone. It is suggested that the hormone may be important in modulating intra- and extra-islet function.
Sensitivity to Oxygen of Nitrogenase Activity in Rhizobium Strain ANU289 of the Non-legume Parasponia (Ulmaceae)
Authors: S Mohapatra S , GresshoffA PM
Published: November 2018

Nitrogenase activity can be detected in Rhizobium strain ANU289 of Parasponia in shaken liquid cultures. A combination of consistently low oxygen tension and appropriate cell density was found to be essential for rapid initiation and high specific rates (in the range of 50-60 nmoles of ethylene per milligram protein per hour). In the presence of succinate as carbon source and an oxygen concentration of 0�25% (v/v) in the gas phase, nitrogenase activity developed after incubation for 24 h. The requirement for an oxygen concentration in the range of O� 1 to 0�35% for derepression indicated a lack of any inherent tolerance to higher oxygen levels and thus suggests that plant-derived mechanisms are responsible for protection by oxygen in the nodule.