bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glutamate and glutamine metabolism in tissues of developing lambs
Authors: Pell Jennifer M. , Tooley Julia , Jeacock Marjorie K. , Shepherd D. A. L. 
Published: March 2009

SUMMARYThe activities of glutamine synthetase, phosphate-dependent glutaminase, phosphate-independent glutaminase, glutamate dehydrogenase, γ-glutamyl transferase and glutamine-oxo-acid aminotransferase were assayed in liver, kidney cortex, brain (cerebral hemispheres), spleen, skeletal muscle and ileum obtained from lambs of 100–260 days conceptual age. A curve was fitted to each set of data relating enzyme activity and conceptual age.In the ileum, glutaminase and γ-glutamyl transferase activities declined during development. Glutamine synthetase activity in the spleen increased markedly after birth, whereas glutamate dehydrogenase activity declined as rumen function was established. In the liver, glutamate dehydrogenase and glutamine synthetase activities were highest in suckling lambs and there was a gradual increase in hepatic γ-glutamyl transferase activity throughout the period studied. The activity of phosphate-dependent glutaminase was lowest in the kidney cortex of ruminating lambs but renal activities of glutamate dehydrogenase, phosphate-independent glutaminase, glutamine synthetase and γ-glutamyl transferase were highest in ruminating lambs. In skeletal muscle, a gradual increase in glutamine synthetase activity occurred after 180 days conceptual age, whereas there was no detectable glutaminase activity in ruminating lambs. In the brain, there was an increase in glutamate dehydrogenase, phosphatedependent glutaminase and glutamine synthetase activities during the foetal and early suckling periods, whereas γ-glutamyl transferase activity increased throughout the period studied.Glutamine-oxo-acid aminotransferase activity was not detected in any of the tissues studied. Phosphate-independent glutaminase activity was always less than 10% of phosphate-dependent glutaminase activity and therefore must have a minor role in the metabolism of glutamine in lambs.A consideration of the relative activities of the enzymes at different stages of development indicated that the ileum, spleen, liver, kidney cortex and brain have a substantial potential for glutamine utilization during foetal life. As a lamb matures after birth, there are changes in the metabolism of glutamate and glutamine which indicate that there is a greater potential for net glutamine synthesis in older lambs. This could be associated with the need for detoxification of ammonia in ruminating lambs.
Soil physical environment affecting root growth of upland rice
Authors: Kar S. , Varade S. B. , Ghildyal B. P. 
Published: March 2009

SUMMARYRoot growth of rice (Oryza saliva L.) is frequentlyinhibited by an adverse physical environment resulting from high moisture stress and strength of soilunder upland conditions, and the effects are often reflected in poor performance of the crop. This necessitates a critical understanding of rice root growth under varying soil physical conditions.The growth responses of the rice root system to the interaction between moisture regime and bulk density of soil as well as to the induced soil physical characteristics were assessed under controlled glasshouse conditions. Four moisture regimes: 0 (M1), 0–20 (M2), 0–350(M3), and 350–10000 (M4) mb, were superimposed on low, medium and high bulk density treatments in clay, loam and sandy loam soils. The soil physical environment was characterized by measurements of moisture distribution, penetrationenergy and oxygen diffusion rate in soils as functions of depth.A low moisture stress of 20 mb in low density soils favoured rice root growth. In low density soils, even though the number of roots at the base (proximal end) was maximum under M1, the depth of penetration, volume and dry weight of root were significantly more underM2 than under M1; M3 and M4. Irrespective of bulk density, even though oxygen diffusion rates in soils under M3 and M4 were greater than those under M1 and M2, the number of roots at the base, volume and dry weight of the root system decreased under M3 and M4 owing to low moisture content and high penetration energy in the surface layer (0–5 cm) of all the soil types. Lower moisture content and higher penetration energy at higher bulk densities of the soil types significantly reduced the root growth and especially the depth of penetration.
Synthetic pheromones to attract honeybee (Apis mellifera) swarms
Authors: Free J. B. , Pickett J. A. , Ferguson A. W. , Smith M. C. 
Published: March 2009

SummaryLures containing the synthetic pheromone components (E)- and (Z)-citrals, geraniol and nerolic and geranic acids made new hives, not previously occupied by honeybee colonies, more attractive to caged honeybee swarms than unbaited hives (20 out of 20 tests). The lure also made old hives, previously occupied by colonies, more attractive to caged swarms (19 out of 20 tests) and to swarms in natural conditions (12 occupied compared with none without the lure). Adding (E)-9-oxo-2-decenoic acid (part of the queen's mandibular gland pheromone) to the lure increased its attractiveness to caged swarms (20 out of 20 tests). Practical implications in beekeeping are discussed.
Pilot survey of the mechanical conditions and fuel consumptions of agricultural tractors
Authors: Slater J. K. W. , Manby T. C. D. 
Published: March 2009

1. A pilot survey was designed to provide information on the mechanical conditions and fuel consumptions of vaporizing oil tractors, on their operation in the field and on the technique required to obtain such data.2. Two areas were chosen offering a contrast in soil and farming types. A sampling frame was prepared for each area in which the farms were grouped according to the number of tractors.
Nitrogen metabolism in the ovine stomach: 4. Nitrogenous components of the abomasal secretions
Authors: Harrop C. J. F. 
Published: March 2009

SUMMARYThe major nitrogenous components of gastric juice were determined in sheep with innervated pouches in the fundic and pyloric regions of the abomasum.Fundic secretions contained mean levels of 36–55 mg total-N/100 ml in the fluid fraction, and pyloric secretions contained 38–70 mg/100 ml. Of this, 65–76% and 75–91% could be attributed to protein, in the fundic and pyloric secretions respectively. Tungstic acid was found to be the most suitable precipitant of proteins in the gastric juice.Dissolved mucin accounted for 2–16% of the total-N in the fluid fraction of the fundic secretions, and for 6–14% in the pyloric secretions. Urea + ammonia contributed 2·8–13·4% of the total-N.The daily output of nitrogen by the fundic region of the abomasum, including that contributed by the cellular debris and visible mucus, was calculated at 0·46–2·4 g. The comparable values for the pyloric region varied between 0·05 and 0·37 g N/day.The electrophoretic patterns of the abomasal secretions were similar to those reported for human gastric juice.
Experiments on the nutrition of the dairy heifer
Authors: Broster W. H. , Smith T. , Broster Valerie J. , Siviter J. W. 
Published: March 2009

SummaryEight experiments, comprising four randomized-block feeding trials each with 20–45 animals and four changeover-design nitrogen (N) balance trials each with 6–10 animals, were used to study the effect of the addition of formaldehyde to fishmeal and to casein, of severe heating of fishmeal, and of tannin treatment of a mixture of vegetable protein-rich foods on the utilization of N for growth. Added in moderate amounts to rations demonstrated within the experiments to be deficient in N, quantities, but not the preparations, of N in the diet were critical to growth save at very low N intakes when the untreated foodstuffs were used more efficiently. Additional energy given in isonitrogenous rations increased growth, reducing N losses in the urine.
The effect of environment and heredity on lactation III. Butterfat percentage
Authors: Mahadevan P. 
Published: March 2009

1. On the basis of 5000 records from twelve leading herds of Ayrshire cattle in south-west Scotland for the period 1930–9, a statistical study has been made of some of the causes of variations which occur in butterfat percentage.2. Butterfat percentage was found to be affected only very slightly by month of calving, age and length of calving intervals.3. Selection for milk yield would not affect butterfat percentage adversely to any appreciable extent.4. The average repeatability of butterfat percentage was 0·691 in the present material, and heritability was of the order of 0·50–0·60.5. Mass selection would be an effective tool in bringing about improvement in butterfat percentage.
A rapid method of data collection and processing
Authors: Rowell J. G. 
Published: March 2009

SUMMARYA method of collecting data in a form suitable for computer analysis is described. Cards are marked in the field or laboratory with a pencil and are read by an optical mark reader which enables the data to be processed by a computer. Accuracy is achieved by verifying a printed list of data as stored by the computer against written figures at the top of the marked cards. Apart from this, no other intermediate step is required and this has enabled a summary of experimental data to be available to the experimenter within one week of collection. Provided an optical mark reader is available locally, the method is inexpensive, involving only computer time and the small cost of cards.
Effects of simultaneous reductions of food intake and dietary protein concentration on the growth and carcass quality of bacon pigs
Authors: Fuller M. F. , English P. R. , Livingstone R. M. , Crofts R. M. J. 
Published: March 2009

SUMMARYDiets containing 10·5, 13, 15·5 or 18% protein were formulated by progressively replacing barley by a 2:1 mixture of soya-bean meal and fish meal. Each diet was given at three levels of intake proportional to (body weight) 0·73. A total of 144 pigs were used at two centres.Growth rate increased with food intake at each protein level, but to the greatest extent with the 13% crude protein (CP) diet. Growth rate also increased with protein level; the results suggested that there would be no further improvement above 18% CP. The effects of protein concentrationon food conversion generally reflected those on daily gain.Carcass fatness, estimated by both midline and introscope measurements of fat thickness and by specific gravity, increased significantly with the intake of all but the 18% protein diet. When theeffects of food intake were taken into account, carcass fatness increased steadily with reductions in protein level down to 13%; the reduction from 13 to 10·5% produced a much greaterincrease in fatness.The reductions in daily food intake necessary to achieve equal carcass fatness as protein level wasreduced were of the order of 0·1 kg per 1% CP from 18% to 13% CP, but ofthe order of 0·3 kg per 1% CP below 13%.Differences between the sexes were greatest at high protein concentration; significant differences between the centres were found only with the low protein diets.
The prediction of voluntary intake of grazing dairy cows
Authors: Caird Lindsey , Holmes W. 
Published: March 2009

SUMMARYInformation on the total organic matter intake, concentrates supplied (C), live weight (LW), week of lactation (WL), milk yield (MY), herbage organic matter digestibility (HOMD), herbage mass, sward height (SHT) or herbage allowance (HAL) measured individually for 357 cows at one of three sites was assembled. Observed intake was compared with intakes predicted by existing intake equations and new prediction equations based on regression models or regression and least-squares constants were developed. Major factors affecting intake were MY, LW, WL, C and HAL or SHT. Although HOMD was correlated with intake, better predictions were obtained when HOMD was omitted. There were differences between sites possibly associated with differences in measurement techniques.The predictive value of some existing equations and new equations were tested against independent sets of data. A simple equation (A) based on MY and LW (Ministry of Agriculture, Fisheries and Food, 1975) gave satisfactory average predictions but the mean square prediction error (MSPE) was high. The equations of Vadiveloo & Holmes (1979) adjusted for bias gave a relatively low MSPE. The preferred new equations for grazing cattle included MY, LW, WL, C and HAL or SHT, and their MSPE were similar to or lower than for indoor equations.The discussion indicates that a simple equation (A) would give adequate predictions for farm planning. The more detailed equations illustrate the inter-relations of animal with sward conditions and concentrate allowances. Predicted intakes may deviate from actual intakes because of short-term changes in body reserves.
Effects of Incorporating or Burning Straw, and of Different Cultivation Systems, on Winter Wheat Grown on Two Soil Types, 1985–91
Authors: Prew R. D. , Ashby J. E. , Bacon E. T. G. , Christian D. G. , Gutteridge R. J. , Jenkyn J. F. , Powell W. , Todd A. D. 
Published: March 2009

SUMMARYDisposal methods for straw from continuous winter wheat were tested on two soil types, a flinty silty clay loam and a sandy loam, over 7 years (1985–91). The methods tested were burnt or chopped straw in full factorial combination with four cultivation methods (tined to 10 cm, tined to 10 cm then to 20 cm; ploughed to 20 cm; tined to 10 cm then ploughed to 20 cm). Measurements were taken to determine the effects on crop establishment and growth, pest and disease incidence, and the consequent effects on yield. Another experiment (1985–91) on the flinty silty clay loam site, investigated the interactions between straw treatments (burnt, baled or chopped in plots that were all shallow cultivated to 10 cm) and five other factors; namely, time of cultivation, insecticides, molluscicides, fungicides and autumn nitrogen. All the straw x cultivation systems allowed satisfactory crops to be established but repeated incorporation of straw using shallow, non-inversion cultivations resulted in very severe grass-weed problems. Early crop growth, as measured by above-ground dry matter production, was frequently decreased by straw residues, but the effect rarely persisted beyond anthesis. Pests were not a problem and their numbers were not greatly affected either by straw or cultivation treatments, apart from yellow cereal fly which, especially on the heavier soil, was decreased by treatments which left much straw debris on the soil surface. Incorporating straw also caused no serious increases in the incidence of diseases. Indeed, averaged over all sites and years, eyespot and sharp eyespot were both slightly but significantly less severe where straw was incorporated than where it was burnt. Eyespot, and even more consistently sharp eyespot, were often more severe after ploughing than after shallow, non-inversion cultivations. Effects on take-all were complex but straw residues had much smaller effects than cultivations. Initially the disease increased most rapidly in the shallow cultivated plots but these also tended to go into the decline phase more quickly so that in the fourth year (fifth cereal crop) take-all was greater in the ploughed than in the shallow cultivated plots. On average, yields did not differ greatly with straw or cultivation systems, although there were clear effects of take-all in those years when the disease was most severe. In the last 2 years, yields were limited by the presence of grass weeds in the plots testing chopped straw incorporated by tining to 10 cm.
Root nitrogen transformation and mineral composition in selected forage legumes
Authors: Nnadi L. A. , Haque I. 
Published: March 2009

SummaryA study was conducted at Debre Zeit, Ethiopia to examine the differences in mineral composition, root N contents and their rates of transformation in the soil of different species of four genera of forage legumes,Trifolium steudneri(ILCA D/Z),Trifolium steudneri(Shola),Vicia dasycarpa(ILCA 6795),Vicia benghalensis, Lablab purpureuscv. Rongai,Lablab purpureuscv. Highworth,Medicago scutellatacv. Snail andMedicago truncatulacv. Barrel.M. truncatulacv. Barrel had higher N and P values thanM. scutellatain both roots and tops. Root N contents of the legumes ranged from 2·43% forViciato 0·87% forLablab. These differences were also reflected in the rates of organic root N transformation in soil as determined in laboratory incubation studies.The P concentration in the tops of the legumes ranged from 0·32% inViciato 0·14% inMedicagospp. The observed P concentration in theMedicagospecies suggests a low internal P requirement. Potassium concentrations in theTrifoliumspecies were much higher than the average for all legumes.The results suggest that theViciaspecies used in this study could contribute a considerable amount of N to subsequent crops even when the tops are not returned to the soil. Also, theMedicagospecies are more likely to thrive better under low soil P conditions than the other legumes.
Different growth strategies in the tropical pioneer treeTrema micranthaduring succession on a large landslide on Casita Volcano, Nicaragua
Authors: Velázquez Eduardo , Gómez-Sal Antonio 
Published: April 2009

Abstract:In this study we examined the size-structures and allometric relationships between height and diameter over 2 y in populations of the pioneer treeTrema micranthaon a large landslide (Casita Volcano, Nicaragua). The landslide comprised three different zones (erosional, depositional and transitional) based on fertility and geomorphological stability. We attempted to analyse the development of canopy hierarchies and intraspecific competition, and the existence of different growth strategies, within theT. micranthapopulations of the different landslide zones. Vegetation was surveyed in 2810 × 10-m plots in which a total number of 307T. micranthaindividuals were recorded and tagged. In the depositional zones, size-hierarchies and one-sided competition for light were apparent and, among the short stems (0.0–2.5 m) of the understorey, plastic responses to shade consisting in a marked increase in height in relation to diameter were evident. In the erosional zones, size-hierarchies were not apparent. All stems were small and, among them, the shortest ones (0.0–1.0 m) were dead whereas the tallest (>1.5 m) grew slowly, increasing their diameter to a greater extent than their height. Our study shows thatT. micranthaindividuals developed different growth strategies in the different areas of the landslide and suggests that this species allocates resources to growth and survival differently depending on environmental conditions.Trema micranthais a highly versatile species capable of dealing not only with extremely infertile substrates and conditions of high light availability, but also with partially shaded environments such as those in secondary forests.
On knot polynomials of annular surfaces and their boundary links
Authors: GRUBER HERMANN 
Published: April 2009

AbstractStoimenow and Kidwell asked the following question: letKbe a non-trivial knot, and letW(K) be a Whitehead double ofK. LetF(a,z) be the Kauffman polynomial andP(v,z) the skein polynomial. Is then always max degzPW(K) − 1 = 2 max degzFK? Here this question is rephrased in more general terms as a conjectured relation between the maximumz-degrees of the Kauffman polynomial of an annular surfaceAon the one hand, and the Rudolph polynomial on the other hand, the latter being defined as a certain Möbius transform of the skein polynomial of the boundary link ∂A. That relation is shown to hold for algebraic alternating links, thus simultaneously solving the conjecture by Kidwell and Stoimenow and a related conjecture by Tripp for this class of links. Also, in spite of the heavyweight definition of the Rudolph polynomial {K} of a linkK, the remarkably simple formula {◯}{L#M} = {L}{M} for link composition is established. This last result can be used to reduce the conjecture in question to the case of prime links.
Maternal depressive symptoms in infancy: Unique contribution to children's depressive symptoms in childhood and adolescence?
Authors: Bureau Jean-François , Easterbrooks M. Ann , Lyons-Ruth Karlen 
Published: April 2009

AbstractThis prospective 20-year study assessed associations between maternal depressive symptoms in infancy, childhood, and adolescence, and child and adolescent depressive symptoms in a sample of families at high psychosocial risk. Maternal symptomatology was assessed with the Center for Epidemiological Studies Depression Scale (CES-D) when children were infants (12 months), school-aged (age 8), and adolescents (age 19). Children's depressive symptoms were measured at age 8 (Dimensions of Depression Profile for Children and Adolescents) and age 19 (CES-D). Maternal depressive symptoms during infancy contributed to the prediction of child depressive symptoms at age 8, after controlling for concurrent maternal depressive symptoms, clinical risk in infancy, and gender. Clinical risk in infancy marginally contributed to the prediction model. Disorganization of attachment in infancy and maternal hostility were independent predictors of depressive symptoms at age 8 and did not mediate the relation between maternal and child depressive symptoms. Depressive symptoms in adolescence were predicted by gender, children's depressive symptoms at age 8, maternal depressive symptoms in adolescence, and maternal depressive symptoms in infancy. There was no moderating effect of gender. Adding to previous evidence on the importance of early maternal depression, maternal depressive symptoms during infancy were related to the development of depressive symptoms in childhood and adolescence even when other variables of potential relevance were controlled.
THE FINITE SUM OF THE PRODUCTS OF TWO TOEPLITZ OPERATORS
Authors: DING XUANHAO 
Published: April 2009

AbstractWe consider in this paper the question of when the finite sum of products of two Toeplitz operators is a finite-rank perturbation of a single Toeplitz operator on the Hardy space over the unit disk. A necessary condition is found. As a consequence we obtain a necessary and sufficient condition for the product of three Toeplitz operators to be a finite-rank perturbation of a single Toeplitz operator.
Snapin associates with late endocytic compartments and interacts with late endosomal SNAREs
Authors: Lu Li , Cai Qian , Tian Jin-Hua , Sheng Zu-Hang 
Published: April 2009

Late endocytic membrane trafficking delivers target materials and newly synthesized hydrolases into lysosomes and is critical for maintaining an efficient degradation process and cellular homoeostasis. Although some features of late endosome–lysosome trafficking have been described, the mechanisms underlying regulation of this event remain to be elucidated. Our previous studies showed that Snapin, as a SNAP25 (25 kDa synaptosome-associated protein)-binding protein, plays a critical role in priming synaptic vesicles for synchronized fusion in neurons. In the present study, we report that Snapin also associates with late endocytic membranous organelles and interacts with the late endosome-targeted SNARE (soluble N-ethylmaleimide-sensitive factor-attachment protein receptor) complex. Using a genetic mouse model, we further discovered that Snapin is required to maintain a proper balance of the late endocytic protein LAMP-1 (lysosome-associated membrane protein-1) and late endosomal SNARE proteins syntaxin 8 and Vti1b (vesicle transport through interaction with target SNAREs homologue 1b). Deleting the snapin gene in mice selectively led to the accumulation of these proteins in late endocytic organelles. Thus our present study suggests that Snapin serves as an important regulator of the late endocytic fusion machinery, in addition to its established role in regulating synaptic vesicle fusion.