bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metabolism of avenanthramide phytoalexins in oats
Authors: Okazaki Yozo , Isobe Taishi , Iwata Yoichi , Matsukawa Tetsuya , Matsuda Fumio , Miyagawa Hisashi , Ishihara Atsushi , Nishioka Takaaki , Iwamura Hajime 
Published: July 2004

SummaryOat leaves produce phytoalexins, avenanthramides, in response to infection by pathogens or treatment with elicitors. The metabolism of avenanthramides was investigated using low molecular weight, partially deacetylated chitin as an elicitor. When oat leaf segments are floated on the elicitor solution, avenanthramides accumulate in the solution. The transfer of elicited oat leaves to solutions containing stable‐isotope‐labeled avenanthramides resulted in a rapid decrease in the labeled avenanthramides, suggesting the metabolism of avenanthramides. The rate of decrease was enhanced by elicitor treatment, and was dependent on the species of avenanthramides, with avenanthramide B decreasing most rapidly. The rates of biosynthesis and metabolism of avenanthramides A and B were measured using a model of isotope‐labeling dynamics. Avenanthramide B was found to be more actively biosynthesized and metabolized than avenanthramide A. Radiolabeled avenanthramide B was incorporated into the cell wall fraction and 99% of incorporated activity was released by alkaline treatment. Gel filtration indicated that high‐molecular‐weight compounds derived from avenanthramide B were released by alkaline treatment. The decrease in stable‐isotope‐labeled avenanthramides was suppressed by catalase, salicylhydroxamic acid, and sodium ascorbate, suggesting the involvement of peroxidase in the metabolism. Consistent with this, peroxidase activity that accepts avenanthramide B as a substrate was induced in apoplastic fractions by elicitor treatment. The appearance of multiple basic isoperoxidases was observed by activity staining with 3‐amino‐9‐ethylcarbazole coupled with isoelectric focusing of proteins from elicitor‐treated leaves. These findings suggest that accumulated avenanthramides are further metabolized in apoplasts in oat leaves by inducible isoperoxidases.
Stromule formation is dependent upon plastid size, plastid differentiation status and the density of plastids within the cell
Authors: Waters Mark T. , Fray Rupert G. , Pyke Kevin A. 
Published: July 2004

SummaryStromules are motile extensions of the plastid envelope membrane, whose roles are not fully understood. They are present on all plastid types but are more common and extensive on non‐green plastids that are sparsely distributed within the cell. During tomato fruit ripening, chloroplasts in the mesocarp tissue differentiate into chromoplasts and undergo major shifts in morphology. In order to understand what factors regulate stromule formation, we analysed stromule biogenesis in tobacco hypocotyls and in two distinct plastid populations in tomato mesocarp. We show that increases in stromule length and frequency are correlated with chromoplast differentiation, but only in one plastid population where the plastids are larger and less numerous. We used tobacco hypocotyls to confirm that stromule length increases as plastids become further apart, suggesting that stromules optimize the plastid–cytoplasm contact area. Furthermore, we demonstrate that ectopic chloroplast components decrease stromule formation on tomato fruit chromoplasts, whereas preventing chloroplast development leads to increased numbers of stromules. Inhibition of fruit ripening has a dramatic impact on plastid and stromule morphology, underlining that plastid differentiation status, and not cell type, is a significant factor in determining the extent of plastid stromules. By modifying the plastid surface area, we propose that stromules enhance the specific metabolic activities of plastids.
A Mixed Modelling Approach for Randomized Experiments with Repeated Measures
Authors: Piepho H. P. , Büchse A. , Richter C. 
Published: July 2004

AbstractRepeated measurements on the same experimental unit are common in plant research. Due to lack of randomization and the serial ordering of observations on the same unit, such data give rise to correlations, which need to be accounted for in statistical analysis. Mixed modelling provides a flexible framework for this task. The present paper proposes a general method to formulate mixed models for designed experiments with repeated measurements. The approach is exemplified by way of several examples.
Environmental and Genotypic Effects on Pod Characteristics Related to Common Bean Quality
Authors: De Ron A. M. , Casquero P. A. , González A. M. , Santalla M. 
Published: July 2004

AbstractA collection of 121 common bean (Phaseolus vulgaris L.) landraces from Spain and Portugal (Iberian Peninsula) was evaluated in six environments (three locations and 2 years). Significant differences among landraces were found for period of flowering, pod maturity and pod morphology (weight, length, width/thickness and curvature). Wide variation among landraces was revealed by the range of variation observed. Environmental effects were not significant although year × location and landrace × year × location interactions were significant for all traits studied except for pod curvature. Poor consistent expression across the different environments for most of the traits studied was expressed by the low values of constancy (C) with the exception of width/thickness indicating that pod shape (round or flat) was expressed regularly across different environments. Principal component analysis enhanced differences among environments affecting the performance of the bean landraces evaluated. Analysis by environment showed that 51 landraces were adapted to specific environments and only four of them had broad geographical adaptability with similar performance under different conditions. These results could be a starting point for selection of new inbred lines adapted to distinct environments with potential for the improvement of current snap bean cultivars.
Comparison of Fatty Acid Metabolism of Two Oleic and One Conventional Sunflower Hybrids: A New Hypothesis
Authors: Lagravère T. , Kleiber D. , Surel O. , Calmon A. , Bervillé A. , Dayde J. 
Published: July 2004

AbstractStudies on oleic sunflower (Helianthus annuus L.) were carried out in order to determine which mechanism produces oleic and linoleic acids in oleic hybrids. The fatty acid composition of different lipid fractions (structural and storage forms) was followed during the achene development of three hybrids including cv. Santiago (non‐oleic hybrid), cv. Olbaril and cv. Trisun 870 (high oleic hybrids). In addition, a simple physiological model of fatty acid accumulation was developed. In order to complete this biochemical approach, a molecular study of desaturase gene accumulation has been preformed. The evolution of oleic and linoleic acid contents in achenes revealed the lack of Δ12‐desaturase activity in oleic hybrids and also indicated differences between oleic genotypes related to linoleic acid content in the first days after pollination and until maturity. Molecular studies (using Northern blot analysis) confirmed that the Δ12‐desaturase transcript was not expressed at the same time in oleic hybrids. These observations were confirmed by studies on the selective dispatching of oleic and linoleic acids in different lipid fractions during achene development. Trisun 870 showed a very low content of linoleic acid in triglycerides throughout achene maturation, whereas Olbaril presented a higher initial content followed by a rapid decrease. These results led us to put forward a new hypothesis for fatty acid biosynthesis in the oleic sunflower hybrids.
Effects of Reduced Tillage and Fertilization Practices on Soil Characteristics, Plant Water Status, Growth and Yield of Upland Cotton
Authors: Karamanos A. J. , Bilalis D. , Sidiras N. 
Published: July 2004

AbstractThree different tillage practices, conventional (mouldboard ploughing at 22–25 cm plus one rotary hoeing at 5–6 cm, CT), minimum (one rotary hoeing at 12–15 cm, MT), and no‐tillage (direct drilling in soil covered by vetch residues, NT), combined with three fertilization treatments, inorganic (50 kg N ha−1 as ammonium sulphate), cattle manuring (30 t ha−1), and control (no‐fertilizer), were applied on a cotton crop (Gossypium hirsutum L. cv. Acala SJ‐2) grown on a clay loam soil in the field of the Agricultural University of Athens. Soil (gravimetric water content, bulk density, and penetration resistance in the top 40 cm) and plant parameters (root growth, leaf water potential, leaf area growth and seedcotton yield) were recorded throughout the cultivation period in all treatments. No‐tillage was associated with significantly higher values of soil water throughout the observation period caused by the vetch mulch. Bulk density and penetration resistance were initially higher in the no‐tilled plots, but they became significantly lower after 2–3 months from sowing. These beneficial effects on soil properties favoured root growth, expressed as root surface density, in the NT‐plots at the top soil layer. Similar, although less spectacular, effects were observed in the manured plots. Plant water status, expressed in terms of the water potential index, was significantly and consistently best in the NT‐ and worst in the CT‐plots throughout crop growth. In addition, NT favoured a better foliage growth and resulted in significantly higher yields than the other tillage practices. In general, NT, and in second instance, MT considerably improved plant water status, and hence foliage growth and yield in comparison with CT by maintaining higher levels of soil water and improving root growth. Manuring positively interacted with the reduced tillage practices for most soil and plant parameters.
Effects of Partial Defoliation on Sucrose Accumulation, Enzyme Activity and Agronomic Parameters in Sugar cane (Saccharum spp.)
Authors: Gutiérrez‐Miceli F. A. , Morales‐Torres R. , De Jesús Espinosa‐Castañeda Y. , Rincón‐Rosales R. , Montes‐Molina J. , Oliva‐Llaven M. A. , Dendooven L. 
Published: July 2004

AbstractMechanical defoliation of sugar cane plants (Saccharum spp.) will provide leaves that can be used as fodder. The effect of partial mechanical defoliation on sucrose content, enzyme activities and agronomic parameters of sugar cane is still unknown. We investigated how sucrose accumulation, activities of sucrose phosphate synthase, soluble acid invertase, sucrose synthase, neutral invertase, brix grades, purity grade, moisture content, fibre content, maturity index and reduced sugars of two commercial sugar cane plants (Mex 69‐290 and Mex 57‐473) were affected in a field experiment. The concentration of sucrose in stems of partial defoliated plants was not significantly different from that found in intact plants. Agronomic parameters and enzyme activities were not different in defoliated plants compared with intact plants except for the moisture content which was higher in defoliated plants than in intact ones. These results indicated that sugar cane plants could be partially defoliated without changing sucrose production and agronomic parameters while providing leaves that could be used as fodder.
Effects of Drought and Competition by a Ryegrass Sward on the Seedling Growth of a Range of Grassland Species
Authors: Hofmann M. , Isselstein J. 
Published: July 2004

AbstractIn de‐intensified grassland where an increased seedling recruitment is seen as a prerequisite to enhance plant species diversity, establishment success of introduced seeds of wildflower species is often poor. Outshading by the existing sward and dry weather spells when seedlings are at an early stage of development are major reasons for a low seedling establishment. The effects of drought and competition by an existing Lolium perenne sward on the growth of seedlings of seven wildflower species were investigated under standardized environmental conditions. Without competition (control), the relative growth rate of the wildflower seedlings varied between 103 (Tragopogon pratensis) and 184 mg g−1 day−1 (Leontodon autumnalis). Species differed in the extent of growth reduction by competition. Compared with the control, reduction of seedling dry weight ranged from 45 % (Trifolium pratense) up to 88 % (Daucus carota). The time range between onset of desiccation and first effects on growth varied between species, with T. pratense showing early and strong growth reduction in contrast to D. carota being least affected. It can be concluded, that those species which maintain a comparatively high growth rate supported by adapted shoot‐root allocation are most promising for establishment in grassland as they can exploit profiles of higher resource availability.
Adipocyte lipolysis, hormonal and metabolic changes in ethanol‐drinking rats
Authors: Szkudelski T. , Bialik I. , Szkudelska K. 
Published: July 2004

SummaryThe effect of ethanol drinking on some hormonal and metabolic changes in the rat and on lipolysis in isolated adipocytes was tested. Male growing Wistar rats divided into two groups were used in the experiment. Ten per cent ethanol solution as the only drinking fluid for 2 weeks depressed body weight gain. The diminution of blood insulin with simultaneous increase in leptin concentration found in these rats suggest that the physiological regulation of leptin secretion is disturbed by ethanol. Liver triglycerides content was substantially augmented due to ethanol ingestion. Adipocytes were isolated from both groups of rats by collagenase digestion and the lipolytic activity of these cells was compared. Isolated cells (106/ml) were incubated for 90 min in Krebs–Ringer buffer (pH 7.4, 37 °C) containing 3 mm glucose and different lipolytic modulators: adrenaline (1 μm), insulin (1 nm), dibutyryl‐cAMP (1 mm) and DPCPX (a selective antagonist of adenosine A1 receptor, 1 μm). To determine basal lipolysis cells were incubated without lipolytic agents. Lipolysis was determined by the amount of glycerol released from cells to the incubation medium. Basal and adrenaline‐induced lipolysis was depressed in adipocytes of ethanol‐drinking rats. The antilipolytic activity of insulin was the same in both groups of isolated cells. Lipolysis induced by dibutyryl‐cAMP was only slightly reduced due to ethanol consumption, whereas triglycerides breakdown evoked by adenosine A1 receptor antagonism was unchanged. Results obtained in vitro indicate that subchronic ethanol drinking attenuates basal and stimulated lipolysis in adipocytes, however, the antilipolytic effect of insulin and the adenosine pathway are unchanged.
Consequences of eicosapentaenoic acid (n‐3) and arachidonic acid (n‐6) supplementation on mast cell mediators
Authors: Gueck T. , Seidel A. , Fuhrmann H. 
Published: July 2004

SummaryMast cells are important players in the pathogenesis of atopic diseases. These cells release immediate‐phase and late‐phase mediators of inflammation. Fatty acids are incorporated in cellular membranes and therefore seem to influence mediator production and release. A study was conducted to assess the effects of eicosapentaenoic acid (EPA, 20:5n‐3) and arachidonic acid (AA, 20:4n‐6) on mast cell mediators in a canine mastocytoma cell line (C2). Cells were cultured in a basic medium (Dulbecco's modified Eagle's medium/HAM's F12 1 : 1, DEH), DEH supplemented with 14.0 μm EPA (DEH‐EPA) or 14 μm AA (DEH‐AA). The DEH‐AA cultured cells had increased spontaneous and mastoparan‐stimulated PGE2 production and histamine release. Furthermore, the tryptase activity was increased. The DEH‐EPA cultured cells rendered elevated levels of PGE2 and histamine release compared with DEH only after stimulation. These levels were significantly lower in comparison to DEH‐AA. The increased PGE2 production of C2 cultured in DEH‐AA is the consequence of the AA enrichment, because AA is the precursor of PGE2. However, the different effects by AA and EPA on mast cell mediators possibly reflect the higher susceptibility of long chain polyunsaturated fatty acids (PUFA) to undergo lipid peroxidation, because it is known that altered cellular redox state influences mediator production and release.
Diurnal rhythm in heat production and oxidation of carbohydrate and fat in pigs during feeding, starvation and re‐feeding
Authors: Chwalibog A. , Tauson A.‐H. , Thorbek G. 
Published: July 2004

SummaryDiurnal rhythm in heat production (HE), oxidation of carbohydrate (OXCHO) and fat (OXF) was calculated from daily measurements of gas exchange in 12 pigs [20–40 kg live weight, (LW)] during 6 days of near ad libitum feeding, followed by 4 days of starvation and 4 days of re‐feeding. All measurements, divided in five times intervals from 12.00 to 8.00, showed the highest values of HE, reflecting the animals’ energy requirements, between 12.00 and 16.00 gradually declining to the lowest values between 4.00 and 8.00. The values measured in the interval 4.00–8.00 were considered as a basal metabolic rate (BMR), being in all measurements 25% lower than during 12.00–4.00. The lowest BMR was measured on the fourth day of starvation (21.7 kJ/h·kg0.75). By transition from feeding to starvation, OXCHO declined gradually, but was for 16 h able to cover the energy requirement with no contribution from OXF. The decline in OXCHO proceeded for 40 h and reached zero between 4.00 and 8.00 on the first day of starvation with the energy requirement being covered by OXF. The HE during starvation was 25–30% lower than during feeding caused by absence of feed‐induced thermogenesis and by the transition from OXCHO to OXF. Immediately after re‐feeding dietary carbohydrates were oxidized, however, there was still a substantial OXF, proceeding until the next feeding. From the second day of re‐feeding the contribution of substrates to the total HE was re‐established with no OXF and the same level of HE as during feeding.
Lipid concentrations of fillets, liver, plasma and lipoproteins of African catfish, Clarias gariepinus (Burchell 1822), fed diets with varying protein concentrations
Authors: Matter F. , Peganova S. , Eder K. 
Published: July 2004

SummaryThis study investigated the effect of the dietary protein concentration on lipid concentrations in fillet and liver and concentrations of lipids in plasma and lipoproteins in African catfish. Two experiments were carried out, in which African catfish were fed diets with various protein concentrations. In experiment 1, semisynthetic diets with various concentrations of casein (350, 450 or 550 g protein/kg) were used. In experiment 2, diets were based on a commercial trout diet supplemented with various amounts of casein or carbohydrates, resulting in protein concentrations between 282 and 545 g/kg diet. In both experiments, the dietary protein concentration had a significant effect on growth, feed conversion ratio and carcass composition. Maximum of body weight gains and feed efficiency ratios were reached in both experiments at the highest dietary protein concentrations. Increasing the dietary protein concentration continuously increased masses of fillets and reduced masses of the liver and adipose tissue in the abdominal cavity. Fish fed the diets with the highest protein concentrations had the lowest concentration of total lipids, triglycerides and cholesterol in the fillets, the highest percentage of polyunsaturated fatty acids (PUFA) in total lipids of fillets and the lowest concentrations of saturated fatty acids (SFA). Fish fed the diets with the highest protein concentration also had the lowest concentrations of triglycerides in the liver, the highest percentages of PUFA in liver total lipids and the lowest percentages of SFA. Moreover, fish fed diets with high protein concentrations (501 and 545 g/kg) had significantly lower concentrations of triglycerides, cholesterol and phospholipids in plasma than fish fed diets with lower protein concentrations. In conclusion, this study shows that the dietary protein concentration does not only influence growth, feed efficiency and carcass composition in African catfish, but also influences their lipid metabolism and lipid concentrations of liver and fillet.
Effect of glycine and vitamin supplementation on sulphur amino acid utilization by growing cattle
Authors: Lambert B. D. , Titgemeyer E. C. , Löest C. A. , Johnson D. E. 
Published: July 2004

SummaryEffects of glycine (Gly) and B‐vitamins on sulphur amino acid (AA) utilization were studied in growing steers maintained under conditions where methionine (Met) was first limiting. Conditions were generated by limit feeding a diet low in ruminally non‐degraded protein and abomasally infusing an AA mixture limiting in Met. Retained N tended (p = 0.07) to improve when steers received 10 mg folate, 10 mg vitamin B6, and 0.10 mg vitamin B12 daily. Hepatic vitamin B12 (p = 0.08) and folate (p = 0.05) concentrations increased with vitamin supplementation. In another trial, factorial treatments were 2 or 5 g/day l‐Met and 0 or 50 g/day Gly infused abomasally. Retained N increased (p < 0.05) in response to Met, and responses were numerically larger in the presence of supplemental Gly. In a different trial, factorial treatments were 0 or 2.4 g/day l‐cysteine (Cys) and 0 or 40 g/day Gly. Retained N was not affected by Cys in the absence of Gly, but was increased by Cys when Gly was supplemented (interaction, p = 0.01). B‐vitamin status may affect sparing of Met by Cys. Supplemental Gly improved responses to supplemental Met and Cys.
Relationship between the in vitro‐estimated utilizable crude protein and the Cornell Net Carbohydrate and Protein System crude protein fractions in feeds for ruminants
Authors: Zhao G. Y. , Cao J. E. 
Published: July 2004

SummaryThe objectives of this experiment were to study the regression relationship between the in vitro‐estimated utilizable crude protein (uCP) and the Cornell Net Carbohydrate and Protein System (CNCPS) crude protein fractions, i.e. PA, PB1, PB2, PB3 and PC of feeds for ruminants, and the possibility of using CNCPS crude protein fractions for the estimation of uCP of feeds for ruminants. The CP, the non‐protein nitrogen (NPN), the soluble cru de protein (SCP), the neutral detergent insoluble crude protein (NDICP) and the acid detergent insoluble crude protein (ADICP) of 30 single feeds were determined and the CP fractions, i.e. PA, PB1, PB2, PB3 and PC, were then calculated based on CNCPS. The uCP of the 30 feeds was estimated using the in vitro incubation technique of Zhao and Lebzien (2000). It was found that there was a significant multiple regression relationship between the uCP [g/kg dry matter (DM)] and the CNCPS crude protein fractions, i.e. PA (% DM), PB1 (% DM), PB2 (% DM), PB3 (% DM) and PC (% DM) of the feed samples. uCP = (9.95 ±2.73)PA + (2.92 ± 1.36)PB1 + (7.24 ± 0.86)PB2 + (8.20 ± 3.33)PB3 + (17.67 ± 3.79) PC + (63.26 ± 18.02), r2 = 0.90, n = 30, p < 0.0001. It was suggested that the multiple regression relationship shown above could be used for the estimation of the uCP of feeds based on the CNCPS crude protein fractions PA, PB1, PB2, PB3 and PC of feeds for ruminants.
International collaboration to address common problems in health care: processes, practicalities and power
Authors: Rolfe M. K. , Bryar R. M. , Hjelm K. , Apelquist J. , Fletcher M. , Anderson B.‐L. 
Published: July 2004

AbstractThis article reports on an international collaborative study into the management of chronic leg ulcers by nurses working in the community in Kronoberg, Sweden and the East Riding and Hull, UK. The management of leg ulcers like many other services provided by nurses working in the community is one that is growing out of community need, often without matching resources. This article reports on some of the processes that were involved and some of the practical considerations that were faced and addressed in formulating and conducting an international collaborative study. The article also explores the ‘power’ international collaboration brings to the research enterprise.