878 research outputs found

    Effect of invader removal: pollinators stay but some native plants miss their new friend

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    Removal of invasive species often benefits biological diversity allowing ecosystems’ recovery. However, it is important to assess the functional roles that invaders may have established in their new areas to avoid unexpected results from species elimination. Invasive animal-pollinated plants may affect the plant–pollination interactions by changing pollinator availability and/or behaviour in the community. Thus, removal of an invasive plant may have important effects on pollinator community that may then be reflected positive or negatively on the reproductive success of native plants. The objective of this study was to assess the effect of removing Oxalis pescaprae, an invasive weed widely spread in the Mediterranean basin, on plant–pollinator interactions and on the reproductive success of co-flowering native plants. For this, a disturbed area in central Portugal, where this species is highly abundant, was selected. Visitation rates, natural pollen loads, pollen tube growth and natural fruit set of native plants were compared in the presence of O. pes-caprae and after manual removal of their flowers. Our results showed a highly resilient pollination network but also revealed some facilitative effects of O. pes-caprae on the reproductive success of co-flowering native plants. Reproductive success of the native plants seems to depend not only on the number and diversity of floral visitors, but also on their efficiency as pollinators. The information provided on the effects of invasive species on the sexual reproductive success of natives is essential for adequate management of invaded areas.This work is financed by FEDER funds through the COMPETE Program and by Portuguese Foundation for Science and Technology (FCT) funds in the ambit of the project PTDC/ BIA-BIC/110824/2009, by CRUP Acc¸o˜es Integradas Luso- Espanholas 2010 with the project E10/10, by MCI-Programa de Internacionalizacio´n de la I ? D (PT2009-0068) and by the Spanish DGICYT (CGL2009-10466), FEDER funds from the European Union, and the Xunta de Galicia (INCITE09- 3103009PR). FCT also supported the work of S. Castro (FCT/ BPD/41200/2007) and J. Costa (CB/C05/2009/209; PTDC/ BIA-BIC/110824/2009). The work of V. Ferrero was supported by the Fundacio´n Ramo´n Areces

    Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

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    Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

    Age influence on effectiveness of a novel 3-phytase in barley-wheat based diets for pigs from 12 to 108 kg under commercial conditions

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    [EN] The main objective of this study was to evaluate the influence of pig's age on the effectiveness of a new microbial 3-phytase, produced by Komagataella phaffii, under commercial conditions in barley-wheat based diets. Two experiments were conducted in weaned, growing and finishing pigs; firstly, to determine phytase efficacy on dry matter, organic matter, energy, protein and mineral (phosphorus, P and calcium, Ca) digestibility (n = 48; Experiment 1), and secondly, to evaluate the effect of phytase on growth performance and bone mineralization (n = 312; Experiment 2). In each experiment, three barley-wheat based diets were formulated following the recommendations for each animal age, of which two versions were manufactured, including 0 and 1000 phytase units (FTU)/kg of feed of the new 3-phytase to be tested. Results showed the new phytase had the potential to increase the digestibility of Ca and P (on av. + 0.05 and +0.06, respectively; P < 0.01), especially P digestibility in growing pigs (+0.10; P < 0.001), consequently decreasing P and Ca excretion. Digestible energy (DE) of the diet increased with the addition of phytase in weaned pigs (+0.69 MJ/kg of dry matter (DM); P < 0.001). Dietary inclusion of new 3-phytase enhanced average daily gain from 46 to 94 days of age (+0.07 kg/d; P < 0.05) and decreased feed conversion ratio from 46 to 154 days of age (on av. -0.13; P < 0.05), although no significant effect was observed from 154 to 185 days of age. Addition of the new 3-phytase also promoted bone mineralization, increasing the weight of the bones (+3.99 and +3.64 g of tibia at 95 days and metacarpus at 100 days of age, respectively; P < 0.05) and the ash, Ca and P content in these bones (e.g. + 0.46 and +0.33 g of P in tibia at 95 days and metacarpus at 100 days of age, respectively; P < 0.001). In conclusion, pig age affected the efficacy of a new 3-phytase on P and Ca digestibility both in weaned and growing diets and DE content of the weaned diets, which also resulted in improvements in growth, feed conversion and bone development until 154 days of age. These effects seem to be reduced during the finishing period, although the advantages of the new 3-phytase on bone mineralization were maintained until 185 days of age.We thank the technical staff at the experimental farms of the Research and Technology Animal Centre (CITA-IVIA), the Institute of Animal Science and Technology (Universitat Politècnica de Valencia) and Javier Gómez (Crianzas Campovivo) for expert technical assistance and experimental support.Cambra López, M.; Cerisuelo, A.; Ferrer, P.; Ródenas Martínez, L.; Aligué, R.; Moset, V.; Pascual Amorós, JJ. (2020). Age influence on effectiveness of a novel 3-phytase in barley-wheat based diets for pigs from 12 to 108 kg under commercial conditions. Animal Feed Science and Technology. 267:1-13. https://doi.org/10.1016/j.anifeedsci.2020.114549S113267Adeola, O., & Cowieson, A. J. (2011). BOARD-INVITED REVIEW: Opportunities and challenges in using exogenous enzymes to improve nonruminant animal production. Journal of Animal Science, 89(10), 3189-3218. doi:10.2527/jas.2010-3715Almeida, F. N., Sulabo, R. C., & Stein, H. H. (2013). Effects of a novel bacterial phytase expressed in Aspergillus Oryzae on digestibility of calcium and phosphorus in diets fed to weanling or growing pigs. Journal of Animal Science and Biotechnology, 4(1). doi:10.1186/2049-1891-4-8Arredondo, M. A., Casas, G. A., & Stein, H. H. (2019). Increasing levels of microbial phytase increases the digestibility of energy and minerals in diets fed to pigs. Animal Feed Science and Technology, 248, 27-36. doi:10.1016/j.anifeedsci.2019.01.001Atakora, J. K. A., Moehn, S., Sands, J. S., & Ball, R. O. (2011). Effects of dietary crude protein and phytase–xylanase supplementation of wheat grain based diets on energy metabolism and enteric methane in growing finishing pigs. Animal Feed Science and Technology, 166-167, 422-429. doi:10.1016/j.anifeedsci.2011.04.030Blaabjerg, K., Nørgaard, J. V., & Poulsen, H. D. (2012). Effect of microbial phytase on phosphorus digestibility in non-heat-treated and heat-treated wheat–barley pig diets1. Journal of Animal Science, 90(suppl_4), 206-208. doi:10.2527/jas.53920Brady, S., Callan, J., Cowan, D., McGrane, M., & O’Doherty, J. (2002). Effect of phytase inclusion and calcium/phosphorus ratio on the performance and nutrient retention of grower-finisher pigs fed barley/wheat/soya bean meal-based diets. Journal of the Science of Food and Agriculture, 82(15), 1780-1790. doi:10.1002/jsfa.1262Braña, D. V., Ellis, M., Castañeda, E. O., Sands, J. S., & Baker, D. H. (2006). Effect of a novel phytase on growth performance, bone ash, and mineral digestibility in nursery and grower-finisher pigs. Journal of Animal Science, 84(7), 1839-1849. doi:10.2527/jas.2005-565Dersjant‐Li, Y., Awati, A., Schulze, H., & Partridge, G. (2014). Phytase in non‐ruminant animal nutrition: a critical review on phytase activities in the gastrointestinal tract and influencing factors. Journal of the Science of Food and Agriculture, 95(5), 878-896. doi:10.1002/jsfa.6998Eeckhout, W., & De Paepe, M. (1994). Total phosphorus, phytate-phosphorus and phytase activity in plant feedstuffs. Animal Feed Science and Technology, 47(1-2), 19-29. doi:10.1016/0377-8401(94)90156-2EMIOLA, A., AKINREMI, O., SLOMINSKI, B., & NYACHOTI, C. M. (2009). Nutrient utilization and manure P excretion in growing pigs fed corn-barley-soybean based diets supplemented with microbial phytase. Animal Science Journal, 80(1), 19-26. doi:10.1111/j.1740-0929.2008.00590.xGonzález-Vega, J. C., Walk, C. L., & Stein, H. H. (2015). Effects of microbial phytase on apparent and standardized total tract digestibility of calcium in calcium supplements fed to growing pigs1. Journal of Animal Science, 93(5), 2255-2264. doi:10.2527/jas.2014-8215Harper, A. F., Kornegay, E. T., & Schell, T. C. (1997). Phytase supplementation of low-phosphorus growing-finishing pig diets improves performance, phosphorus digestibility, and bone mineralization and reduces phosphorus excretion. Journal of Animal Science, 75(12), 3174. doi:10.2527/1997.75123174xHaug, W., & Lantzsch, H.-J. (1983). Sensitive method for the rapid determination of phytate in cereals and cereal products. Journal of the Science of Food and Agriculture, 34(12), 1423-1426. doi:10.1002/jsfa.2740341217Heaney, R. P., Abrams, S., Dawson-Hughes, B., Looker, A., Looker, A., Marcus, R., … Weaver, C. (2001). Peak Bone Mass. Osteoporosis International, 11(12), 985-1009. doi:10.1007/s001980070020Jørgensen, B. (1995). Effect of different energy and protein levels on leg weakness and osteochondrosis in pigs. Livestock Production Science, 41(2), 171-181. doi:10.1016/0301-6226(94)00048-cKemme, P. A., Jongbloed, A. W., Mroz, Z., & Beynen, A. C. (1997). The efficacy of Aspergillus niger phytase in rendering phytate phosphorus available for absorption in pigs is influenced by pig physiological status. Journal of Animal Science, 75(8), 2129. doi:10.2527/1997.7582129xKiela, P. R., & Ghishan, F. K. (2016). Physiology of Intestinal Absorption and Secretion. Best Practice & Research Clinical Gastroenterology, 30(2), 145-159. doi:10.1016/j.bpg.2016.02.007Kim, J. C., Simmins, P. H., Mullan, B. P., & Pluske, J. R. (2005). The effect of wheat phosphorus content and supplemental enzymes on digestibility and growth performance of weaner pigs. Animal Feed Science and Technology, 118(1-2), 139-152. doi:10.1016/j.anifeedsci.2004.08.016Koch, M. E., & Mahan, D. C. (1985). Biological Characteristics for Assessing Low Phosphorus Intake in Growing Swine. Journal of Animal Science, 60(3), 699-708. doi:10.2527/jas1985.603699xKonietzny, U., & Greiner, R. (2002). Molecular and catalytic properties of phytate-degrading enzymes (phytases). International Journal of Food Science and Technology, 37(7), 791-812. doi:10.1046/j.1365-2621.2002.00617.xLittell, R. C., Henry, P. R., & Ammerman, C. B. (1998). Statistical analysis of repeated measures data using SAS procedures. Journal of Animal Science, 76(4), 1216. doi:10.2527/1998.7641216xMahan, D. C. (1982). Dietary Calcium and Phosphorus Levels for Weanling Swine. Journal of Animal Science, 54(3), 559-564. doi:10.2527/jas1982.543559xMavromichalis, I., Hancock, J. D., Kim, I. H., Senne, B. W., Kropf, D. H., Kennedy, G. A., … Behnke, K. C. (1999). Effects of omitting vitamin and trace mineral premixes and(or) reducing inorganic phosphorus additions on growth performance, carcass characteristics, and muscle quality in finishing pigs. Journal of Animal Science, 77(10), 2700. doi:10.2527/1999.77102700xMoehn, S., Atakora, J. K. A., Sands, J., & Ball, R. O. (2007). Effect of phytase-xylanase supplementation to wheat-based diets on energy metabolism in growing–finishing pigs fed ad libitum. Livestock Science, 109(1-3), 271-274. doi:10.1016/j.livsci.2007.01.118Oryschak, M. A., Simmins, P. H., & Zijlstra, R. T. (2002). Effect of dietary particle size and carbohydrase and/or phytase supplementation on nitrogen and phosphorus excretion of grower pigs. Canadian Journal of Animal Science, 82(4), 533-540. doi:10.4141/a02-016Peter, C. ., Parr, T. ., Parr, E. ., Webel, D. ., & Baker, D. . (2001). The effects of phytase on growth performance, carcass characteristics, and bone mineralization of late-finishing pigs fed maize–soyabean meal diets containing no supplemental phosphorus, zinc, copper and manganese. Animal Feed Science and Technology, 94(3-4), 199-205. doi:10.1016/s0377-8401(01)00300-5Rodehutscord, M., Faust, M., & Lorenz, H. (1996). Digestibility of phosphorus contained in soybean meal, barley, and different varieties of wheat, without and with supplemental phytase fed to pigs and additivity of digestibility in a wheatsoybean-meal diet. Journal of Animal Physiology and Animal Nutrition, 75(1-5), 40-48. doi:10.1111/j.1439-0396.1996.tb00466.xSelle, P. H., & Ravindran, V. (2008). Phytate-degrading enzymes in pig nutrition. Livestock Science, 113(2-3), 99-122. doi:10.1016/j.livsci.2007.05.014Selle, P. H., Cadogan, D. J., & Bryden, W. L. (2003). Effects of phytase supplementation of phosphorus-adequate, lysine-deficient, wheat-based diets on growth performance of weaner pigs. Australian Journal of Agricultural Research, 54(3), 323. doi:10.1071/ar02121She, Y., Su, Y., Liu, L., Huang, C., Li, J., Li, P., … Piao, X. (2015). Effects of microbial phytase on coefficient of standardized total tract digestibility of phosphorus in growing pigs fed corn and corn co-products, wheat and wheat co-products and oilseed meals. Animal Feed Science and Technology, 208, 132-144. doi:10.1016/j.anifeedsci.2015.07.011Van Soest, P. J., Robertson, J. B., & Lewis, B. A. (1991). Methods for Dietary Fiber, Neutral Detergent Fiber, and Nonstarch Polysaccharides in Relation to Animal Nutrition. Journal of Dairy Science, 74(10), 3583-3597. doi:10.3168/jds.s0022-0302(91)78551-2Varley, P. F., Callan, J. J., & O’Doherty, J. V. (2011). Effect of dietary phosphorus and calcium level and phytase addition on performance, bone parameters, apparent nutrient digestibility, mineral and nitrogen utilization of weaner pigs and the subsequent effect on finisher pig bone parameters. Animal Feed Science and Technology, 165(3-4), 201-209. doi:10.1016/j.anifeedsci.2011.02.017Varley, P. F., Flynn, B., Callan, J. J., & O’Doherty, J. V. (2011). Effect of phytase level in a low phosphorus diet on performance and bone development in weaner pigs and the subsequent effect on finisher pig bone development. Livestock Science, 138(1-3), 152-158. doi:10.1016/j.livsci.2010.12.014Vipperman, P. E., Peo, E. R., & Cunningham, P. J. (1974). Effect of Dietary Calcium and Phosphorus Level upon Calcium, Phosphorus and Nitrogen Balance in Swine. Journal of Animal Science, 38(4), 758-765. doi:10.2527/jas1974.384758

    Parameter selection for and implementation of a web-based decision-support tool to predict extubation outcome in premature infants

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    BACKGROUND: Approximately 30% of intubated preterm infants with respiratory distress syndrome (RDS) will fail attempted extubation, requiring reintubation and mechanical ventilation. Although ventilator technology and monitoring of premature infants have improved over time, optimal extubation remains challenging. Furthermore, extubation decisions for premature infants require complex informational processing, techniques implicitly learned through clinical practice. Computer-aided decision-support tools would benefit inexperienced clinicians, especially during peak neonatal intensive care unit (NICU) census. METHODS: A five-step procedure was developed to identify predictive variables. Clinical expert (CE) thought processes comprised one model. Variables from that model were used to develop two mathematical models for the decision-support tool: an artificial neural network (ANN) and a multivariate logistic regression model (MLR). The ranking of the variables in the three models was compared using the Wilcoxon Signed Rank Test. The best performing model was used in a web-based decision-support tool with a user interface implemented in Hypertext Markup Language (HTML) and the mathematical model employing the ANN. RESULTS: CEs identified 51 potentially predictive variables for extubation decisions for an infant on mechanical ventilation. Comparisons of the three models showed a significant difference between the ANN and the CE (p = 0.0006). Of the original 51 potentially predictive variables, the 13 most predictive variables were used to develop an ANN as a web-based decision-tool. The ANN processes user-provided data and returns the prediction 0–1 score and a novelty index. The user then selects the most appropriate threshold for categorizing the prediction as a success or failure. Furthermore, the novelty index, indicating the similarity of the test case to the training case, allows the user to assess the confidence level of the prediction with regard to how much the new data differ from the data originally used for the development of the prediction tool. CONCLUSION: State-of-the-art, machine-learning methods can be employed for the development of sophisticated tools to aid clinicians' decisions. We identified numerous variables considered relevant for extubation decisions for mechanically ventilated premature infants with RDS. We then developed a web-based decision-support tool for clinicians which can be made widely available and potentially improve patient care world wide

    Incidence of dental caries in primary dentition and risk factors: a longitudinal study

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    Abstract The objectives of this prospective, longitudinal, population-based study were to estimate the incidence of dental caries in the primary dentition, identify risk factors and determine the proportion of children receiving dental treatment, through a two-year follow up. The first dental exam was conducted with 381 children aged one to five years, at health centers during immunization campaigns; 184 of them had dental caries and 197 had no caries experience. The second exam was carried out two years later at a nursery or at home with the same individuals who participated in the first exam. The diagnosis of dental caries was performed using the dmft criteria. Parents were interviewed regarding socioeconomic indicators. Descriptive, bivariate and adjusted Poisson regression analyses were performed. Among the 381 children, 234 were reexamined after two years (non-exposed: 139; exposed: 95). The overall incidence of dental caries was 46.6%. The greatest incidence of dental caries was found in the group of children with previous caries experience (61.1%). Among the children without dental caries in the first exam, 36.7% exhibited caries in the second exam. The majority of children (72.6%) received no treatment for carious lesions in the two-year interval between examinations. Children with previous dental caries (RR: 1.52, 95%CI: 1.12–2.05) had a greater risk of developing new lesions, compared with the children without previous dental caries. The incidence of dental caries was high and most of children’s caries were untreated. Previous caries experience is a risk factor for developing new carious lesions in children

    Predicting site index from climate and soil variables for cork oak (Quercus suber L.) stands in Portugal

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    Site productivity, assessed through site index, was modelled using partial least squares regression as a function of soil and climatic variables. Two alternative models were developed: a full model, considering all available explanatory variables, and a reduced model, considering only variables that can be obtained without digging a soil pit. The reduced model was used for mapping the site index distribution in Portugal, on the basis of existing digital cartography available for the whole country. The developed models indicate the importance of water availability and soil water holding capacity for site index value distribution. Site index was related to climate, namely evaporation and frost, and soil characteristics such as lithology, soil texture, soil depth, thickness of the A horizon and soil classification. The variability of the estimated values within the map (9.5–16.8 m with an average value of 13.4 m) reflects the impact of soil characteristics on the site productivity estimation. These variables should be taken into consideration during the establishment of new plantations of cork oak, and management of existing plantations. Results confirm the potential distribution of cork oak in coastal regions. They also suggest the existence of a considerable area, located both North and South of the Tagus river, where site indices values of medium (]13;15]) to high (]15;17]) productivity classes may be expected. The species is then expected to be able to have good productivity along the northern coastal areas of Portugal, where presently it is not a common species but where, according to historical records, it occurred until the middle of the sixteenth century. The present research focused on tree growth. Cork growth and cork quality distribution needs to be further researched through the establishment of long term experimental sites along the distribution area of cork oak, namely in the central and northern coastal areas of the countryinfo:eu-repo/semantics/publishedVersio

    Geometric morphometrics of corolla shape: Dissecting components of symmetric and asymmetric variation in <i>Erysimum mediohispanicum </i>(Brassicaceae)

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    Symmetry is an important feature of floral structure, and floral symmetries are diverse and often complex. We use a new morphometric approach for analysing shapes with complex types of symmetry, which partitions shape variation into a component of symmetric variation and different components of asymmetry. This approach, based on the mathematical theory of symmetry groups, can be used for landmark configurations with any type of symmetry and is therefore promising as a general framework for morphometric analyses of floral symmetry and asymmetry. We demonstrate this approach by quantifying floral shape variation in a wild population of Erysimum mediohispanicum (Brassicaceae). Flowers of this species are disymmetric, so that the symmetry in the left-right and adaxial-abaxial directions can be considered separately and in combination. Both principal component analysis and Procrustes ANOVA indicate that symmetric variation accounts for most of the total variance and that adaxial-abaxial asymmetry is the dominant component of fluctuating asymmetry. Each component is associated with specific patterns of shape variation. These results illustrate the potential of the new method and suggest new areas for future research. The new morphometric approach is promising for further analyses of floral symmetry and asymmetry in evolutionary and developmental contexts. © 2012 New Phytologist Trust
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