Effect of nitrogen and phosphorus supply on growth, chlorophyll content and tissue composition of the macroalga Chaetomorpha linum (O.F. Mull), Kutz, in a Mediterranean Coastal Lagoon

The effect of dissolved nutrients on growth, nutrient content and uptake rates of Chaetomorpha linum in a Mediterranean coastal lagoon (Tancada, Ebro delta, NE Spain) was studied in laboratory experiments. Water was enriched with distinct forms of nitrogen, such as nitrate or ammonium and phosphorus. Enrichment with N, P or with both nutrients resulted in a significant increase in the tissue content of these nutrients. N-enrichment was followed by an increase in chlorophyll content after 4 days of treatment, although the difference was only significant when nitrate was added without P. P-enrichment had no significant effect on chlorophyll content. In all the treatments an increase in biomass was obseved after 10 days. This increase was higher in the N+P treatments. In all the treatments the uptake rate was significantly higher when nutrients were added than in control jars. The uptake rate of N, as ammonium, and P were significantly higher when they were added alone while that of N as nitrate was higher in the N+P treatment. In the P-enriched cultures, the final P-content of macroalgal tissues was ten-fold that of the initial tissue concentrations, thereby indicating luxury P-uptake. Moreover, at the end of the incubation the N:P ratio increased to 80, showing that P rather than N was the limiting factor for C. linum in the Tancada lagoon. The relatively high availability of N is related to the N inputs from rice fields that surround the lagoon and to P binding in sediments.

Customization, transparency and proximity: a user- centered content strategy applied to the design of a virtual library website

We present a case study of the redesign of the organizational presentation and content of the Virtual Library website at the Universitat Oberta de Catalunya (Open University of Catalonia, UOC), based on a user-centered design strategy. The aim of the redesign was to provide users with more intuitive, usable and understandable content (textual content, resources and services) by implementing criteria of customization, transparency and proximity. The study also presents a selection of best practices for applying these criteria to the design of other library websites.

Comparison of fatty acid profiles of edible meat, adipose tissues and muscles between cocks and capons

The effect of caponisation on fat composition by parts (wing, breast, thigh, and drumstick) and tissues (skin, subcutaneous adipose tissue, intermuscular adipose tissue and muscle) was examined in the present study and fatty acid profiles of abdominal fat and edible meat by parts and tissue components were determined. The sample was made up of twenty-eight castrated and twenty male Penedesenca Negra chicks reared under free-range conditions and slaughtered at 28 wk of age; the birds were castrated at four or eight weeks. Caponisation significantly increased (P < 0.01) the chemical fat content in all parts (16.31% to 37.98% in breast; 21.98% to 34.13% in wing; 21.09% to 49.57% in thigh; 14.33% to 24.82% in drumstick) and led to minor modifications in fat haracteristics, particularly in the thigh and the drumstick, where the unsaturated vs. saturated fatty acid ratio increased from 1.31 to 1.76 ( P < 0.01) and from 1.48 to 2.07 (P < 0.01), respectively. Delaying the age of castration from 4 to 8 weeks increased this ratio by 0.35 in the edible meat. Even though the profile of the abdominal fat is less saturated in capons, all changes occurring on fat quality after caponisation indicate that increased fatness after castration does not imply worse fat nutritional properties.

Variation of grain nitrogen content in relation with grain yield in old and modern Spanish wheats grown under a wide range of agronomic conditions in a Mediterranean region

Wheat yield and grain nitrogen concentration (GNC; mg N/g grain) are frequently negatively correlated. In most growing conditions, this is mainly due to a feedback process between GNC and the number of grains/m2. In Mediterranean conditions, breeders may have produced cultivars with conservative grain set. The present study aimed at clarifying the main physiological determinants of grain nitrogen accumulation (GNA) in Mediterranean wheat and to analyse how breeding has affected them. Five field experiments were carried out in north-eastern Spain in the 2005/06 and 2006/ 07 growing seasons with three cultivars released at different times and an advanced line. Depending on the experiment, source-sink ratios during grain filling were altered by reducing grain number/m2 either through pre-anthesis shading (unshaded control or 0.75 shading only between jointing and anthesis) or by directly trimming the spikes after anthesis and before the onset of the effective grain filling period (un-trimmed control or spikes halved 7–10 days after anthesis). Grain nitrogen content (GN content ; mg N/grain) decreased with the year of release of the genotypes. As the number of grains/m2 was also increased by breeding there was a clear dilution effect on the amount of nitrogen allocated to each grain. However, the increase in GN content in old genotypes did not compensate for the loss in grain nitrogen yield (GNY) due to the lower number of grains/m2. GN content of all genotypes increased (increases ranged from 0.13 to 0.40 mg N/grain, depending on experiment and genotype) in response to the post-anthesis spike trimming or pre-anthesis shading. The degree of source-limitation for GNA increased with the year of release of the genotypes (and thus with increases in grain number/m2) from 0.22 (mean of the four manipulative experiments) in the oldest cultivar to 0.51 (mean of the four manipulative experiments) in the most modern line. It was found that final GN content depended strongly on the source-sink ratio established at anthesis between the number of grains set and the amount of nitrogen absorbed at this stage. Thus, Mediterranean wheat breeding that improved yield through increases in grain number/m2 reduced the GN content by diluting a rather limited source of nitrogen into more grains. This dilution effect produced by breeding was further confirmed by the reversal effect produced by grain number/m2 reductions due to either pre-anthesis shading or post-anthesis spike trimming.

Grain yield, carbon isotope discrimination and mineral content in mature kernels of barley under irrigated and rainfed conditions

The relationship between yield, carbon isotope discrimination and ash content in mature kernels was examined for a set of 13 barley (Hordeum vulgare) cultivars. Plants were grown under rainfed and well-irrigated conditions in a Mediterranean area. Water deficit caused a decrease in both grain yield and carbon isotope discrimination (Δ). The yield was positively related to Δ and negatively related to ash content, across genotypes within each treatment. However, whereas the correlation between yield and Δ was higher for the set of genotypes under well-irrigated (r=0.70, P<0.01) than under rainfed (r=0.42) conditions, the opposite occurred when yield and ash content were related, ie r=-0.38 under well-irrigated and r=-0.73, (P<0.01) under rainfed conditions. Carbon isotope discrimination and ash content together account for almost 60% of the variation in yield, in both conditions. There was no significant relationship (r=-0.15) between carbon isotope discrimination and ash content in well-irrigated plants, whereas in rainfed plants, this relationship, although significant (r=-0.54, P< 0.05), was weakly negative. The concentration of several mineral elements was measured in the same kernels. The mineral that correlated best with ash content, yield and A, was K. For yield and Δ, although the relationship with K followed the same pattern as the relationhip with ash content, the correlation coefficients were lower. Thus, mineral accumulation in mature kernels seems to be independent of transpiration efficiency. In fact, filling of grains takes place through the phloem pathway. The ash content in kernels is proposed as a complementary criterion, in addition to kernel Δ, to assess genotype differences in barley grain yield under rainfed conditions.

Reduction of conjugated dienoic carboxylic acids and esters with sodium dithionite

Reduction of 2,4-alkadienoic acids and esters with sodium dithionite was carried out in aqueous solution or under PTC conditions to give, almost exclusively, Z:E isomeric mixtures of the corresponding 3-alkenoic acids and esters, respectively, in good yields.

Semantic data integration in a newspaper content management system

A newspaper content management system has to deal with a very heterogeneous information space as the experience in the Diari Segre newspaper has shown us. The greatest problem is to harmonise the different ways the involved users (journalist, archivists...) structure the newspaper information space, i.e. news, topics, headlines, etc. Our approach is based on ontology and differentiated universes of discourse (UoD). Users interact with the system and, from this interaction, integration rules are derived. These rules are based on Description Logic ontological relations for subsumption and equivalence. They relate the different UoD and produce a shared conceptualisation of the newspaper information domain.

Content value chains modelling using a copyright ontology

Existing digital rights management (DRM) systems, initiatives like Creative Commons or research works as some digital rights ontologies provide limited support for content value chains modelling and management. This is becoming a critical issue as content markets start to profit from the possibilities of digital networks and the World Wide Web. The objective is to support the whole copyrighted content value chain across enterprise or business niches boundaries. Our proposal provides a framework that accommodates copyright law and a rich creation model in order to cope with all the creation life cycle stages. The dynamic aspects of value chains are modelled using a hybrid approach that combines ontology-based and rule-based mechanisms. The ontology implementation is based on Web Ontology Language and Description Logic (OWL-DL) reasoners, are directly used for license checking. On the other hand, for more complex aspects of the dynamics of content value chains, rule languages are the choice.

Forage preservation (grazing vs. hay) fed to ewes affects the fatty acid profile of milk and CPT1B gene expression in the sheep mammary gland

Background: Alterations in lipid metabolism occur when animals are exposed to different feeding systems. In the last few decades, the characterisation of genes involved in fat metabolism and technological advances have enabled the study of the effect of diet on the milk fatty acid (FA) profile in the mammary gland and aided in the elucidation of the mechanisms of the response to diet. The aim of this study was to evaluate the effect of different forage diets (grazing vs. hay) near the time of ewe parturition on the relationship between the fatty acid profile and gene expression in the mammary gland of the Churra Tensina sheep breed. Results: In this study, the forage type affected the C18:2 cis-9 trans-11 (CLA) and long-chain saturated fatty acid (LCFA) content, with higher percentages during grazing than during hay feeding. This may suggest that these FAs act as regulatory factors for the transcriptional control of the carnitine palmitoyltransferase 1B (CPT1B) gene, which was more highly expressed in the grazing group (GRE). The most highly expressed gene in the mammary gland at the fifth week of lactation is CAAT/ enhancer- binding protein beta (CEBPB), possibly due to its role in milk fat synthesis in the mammary gland. More stable housekeeping genes in the ovine mammary gland that would be appropriate for use in gene expression studies were ribosomal protein L19 (RPL19) and glyceraldehyde- 3- phosphate dehydrogenase (GAPDH). Conclusions: Small changes in diet, such as the forage preservation (grazing vs. hay), can affect the milk fatty acid profile and the expression of the CPT1B gene, which is associated with the oxidation of fatty acids. When compared to hay fed indoors, grazing fresh low mountain pastures stimulates the milk content of CLA and LCFA via mammary uptake. In this sense, LCFA in milk may be acting as a regulatory factor for transcriptional control of the CPT1B gene, which was more highly expressed in the grazing group.

Meat characteristics of chickens from an F1 cross of two improved Spanish breeds depending on slaughter age

The present study analysed the meat characteristics of i) improved Castellana Negra chickens slaughtered at 18 weeks (CN-18) and ii) F1 crossbred chickens from improved Castellana Negra hens and improved Penedesenca Negra cocks (CNPN) slaughtered at 12 weeks and 18 weeks of age (young and adult animals, respectively). Purebred and crossbred specimens were compared at similar weights (CN-18 and CNPN-12) and ages (CN-18 and CNPN-18). The protein content of the meat was similar for the three types of animals; heavier animals (CNPN-18) had more fat than those slaughtered at lower weights (CNPN-12 and CN-18). Adults had a higher saturated fatty acid content and the young CNPN chickens had more monounsaturated fatty acids than CN chickens. In the CNPN adults, less water was lost during cooking, which is directly related to the juiciness of the meat. With regard to sensory analysis, a darker colour was observed in the meat as much as the internal fat of adult animals, in addition to greater colour uniformity. The meat of young CNPN birds was juicier, whereas that of the CN chickens was more fibrous. Therefore, we conclude that meat from CNPN chickens presents chemical, physical, and sensorial characteristics that make these animals a genetic base for alternative poultry production.

Customization, transparency and proximity: a user- centered content strategy applied to the design of a virtual library website

We present a case study of the redesign of the organizational presentation and content of the Virtual Library website at the Universitat Oberta de Catalunya (Open University of Catalonia, UOC), based on a user-centered design strategy. The aim of the redesign was to provide users with more intuitive, usable and understandable content (textual content, resources and services) by implementing criteria of customization, transparency and proximity. The study also presents a selection of best practices for applying these criteria to the design of other library websites.

Treatment of rats with a self-selected hyperlipidic diet, increases the lipid content of the main adipose tissue sites in a proportion similar to that of the lipids in the rest of organs and tissues

Adipose tissue (AT) is distributed as large differentiated masses, and smaller depots covering vessels, and organs, as well as interspersed within them. The differences between types and size of cells makes AT one of the most disperse and complex organs. Lipid storage is partly shared by other tissues such as muscle and liver. We intended to obtain an approximate estimation of the size of lipid reserves stored outside the main fat depots. Both male and female rats were made overweight by 4-weeks feeding of a cafeteria diet. Total lipid content was analyzed in brain, liver, gastrocnemius muscle, four white AT sites: subcutaneous, perigonadal, retroperitoneal and mesenteric, two brown AT sites (interscapular and perirenal) and in a pool of the rest of organs and tissues (after discarding gut contents). Organ lipid content was estimated and tabulated for each individual rat. Food intake was measured daily. There was a surprisingly high proportion of lipid not accounted for by the main macroscopic AT sites, even when brain, liver and BAT main sites were discounted. Muscle contained about 8% of body lipids, liver 1-1.4%, four white AT sites lipid 28-63% of body lipid, and the rest of the body (including muscle) 38-44%. There was a good correlation between AT lipid and body lipid, but lipid in"other organs" was highly correlated too with body lipid. Brain lipid was not. Irrespective of dietary intake, accumulation of body fat was uniform both for the main lipid storage and handling organs: large masses of AT (but also liver, muscle), as well as in the"rest" of tissues. These storage sites, in specialized (adipose) or not-specialized (liver, muscle) tissues reacted in parallel against a hyperlipidic diet challenge. We postulate that body lipid stores are handled and regulated coordinately, with a more centralized and overall mechanisms than usually assumed.

Effect of feed fat by-products with trans fatty acids and heated oil on cholesterol and oxycholesterols in chicken

Chicken is the most widely consumed meat all over the world due to chickens being easy to rear, their fast growth rate and the meat having good nutritional characteristics. The main objective of this paper was to study the effects of dietary fatty by-products in low, medium and high levels of oxidized lipids and trans fatty acids (TFAs) on the contents of cholesterol and oxycholesterols in meat, liver, and plasma of chickens. A palm fatty acid distillate, before and after hydrogenation, and a sunflower-olive oil blend (70/30, v/v) before and after use in a commercial frying process were used in feeding trials after adding 6% of the fats to the feeds. Highly oxidized lipid and TFA feeds significantly increased the contents of cholesterol and oxycholesterols in all tissues of chicken (0.01 < p <= 0.05). The contents of oxycholesterols in chicken meat, liver and plasma obtained from TFA feeding trials varied between 17 and 48 μg/100 g in meat, 19-42 μg/100 g in liver and 105-126 μg/dL in plasma. In contrast, in the oxidized lipid feeding trials, oxycholesterols varied between 13 and 75 μg/100 g in meat, 30-58 μg/100 g in liver and 66-209 μg/dL in plasma. Meat from chickens fed with feeds containing high levels of TFAs or oxidized lipids may contribute to higher ingestion of cholesterol and oxycholesterols by humans.

Nuclear DNA content variation in life history phases of the Bonnemaisoniaceae (Rhodophyta)

Nuclear DNA content in gametophytes and sporophytes or the prostrate phases of the following species of Bonnemaisoniaceae (Asparagopsis armata, Asparagopsis taxiformis, Bonnemaisonia asparagoides, Bonnemaisonia clavata and Bonnemaisonia hamifera) were estimated by image analysis and static microspectrophotometry using the DNA-localizing fluorochrome DAPI (4′, 6-diamidino-2-phenylindole, dilactate) and the chicken erythrocytes standard. These estimates expand on the Kew database of DNA nuclear content. DNA content values for 1C nuclei in the gametophytes (spermatia and vegetative cells) range from 0.5 pg to 0.8 pg, and for 2C nuclei in the sporophytes or the prostrate phases range from 1.15-1.7 pg. Although only the 2C and 4C values were observed in the sporophyte or the prostrate phase, in the vegetative cells of the gametophyte the values oscillated from 1C to 4C, showing the possible start of endopolyploidy. The results confirm the alternation of nuclear phases in these Bonnemaisoniaceae species, in those that have tetrasporogenesis, as well as those that have somatic meiosis. The availability of a consensus phylogenetic tree for Bonnemaisoniaceae has opened the way to determine evolutionary trends in DNA contents. Both the estimated genome sizes and the published chromosome numbers for Bonnemaisoniaceae suggest a narrow range of values consistent with the conservation of an ancestral genome.

Metabolic origin of δ15N values in nitrogenous compounds from Brassica napus L. leaves

Nitrogen isotope composition (δ15N) in plant organic matter is currently used as a natural tracer of nitrogen acquisition efficiency. However, the δ15N value of whole leaf material does not properly reflect the way in which N is assimilated because isotope fractionations along metabolic reactions may cause substantial differences among leaf compounds. In other words, any change in metabolic composition or allocation pattern may cause undesirable variability in leaf δ15N. Here, we investigated the δ15N in different leaf fractions and individual metabolites from rapeseed (Brassica napus) leaves. We show that there were substantial differences in δ15N between nitrogenous compounds (up to 30 ) and the content in (15N enriched) nitrate had a clear influence on leaf δ15N. Using a simple steady-state model of day metabolism, we suggest that the δ15N value in major amino acids was mostly explained by isotope fractionation associated with isotope effects on enzyme-catalysed reactions in primary nitrogen metabolism. δ15N values were further influenced by light versus dark conditions and the probable occurrence of alternative biosynthetic pathways. We conclude that both biochemical pathways (that fractionate between isotopes) and nitrogen sources (used for amino acid production) should be considered when interpreting the δ15N value of leaf nitrogenous compounds