Wheat response to CO2 enrichment: CO2 exchanges transpiration and mineral uptakes

When simulating canopies planted in varied densities, researchers were able to demonstrate that increase of dry matter production by enhancing CO2 quickly becomes independant of increase of leaf area, especially above leaf area index of 2; dry matter gain results mainly from photosynthesis stimulation per unit of surface (primary CO2 effect). When crop density is low (the plants remaining alone a longer time), the effects of increasing leaf surface (tillering, leaf elongation here, branching for other plants etc.) was noticeable and dry matter simulation factor reached 1.65. This area effect decreased when canopy was closed in, as the effect of different surfaces no longer worked. The stimulation of photosynthesis reached to the primary CO2 effect. The accumulation in dry matter which was fast during that phase made the original weight advantage more and more neglectible. Comparison with short term measurements showed that first order long term effect of CO2 in wheat is predictible with short term experiment, from the effect of CO2 on photosynthesis measured on reference sample

Study of the relationship between photosynthesis, respiration, transpiration, and mineral nutrition in wheat

The growth of wheat (triticum aestivum) was studied in an enclosed controlled environment for a period of 70 days. The exchange of gases (photosynthesis, respiration), water (transpiration) and the consumption of mineral elements (nitrogen, phosphorus, potassium) were continuously measured. The dynamical relations observed in the different physiological functions, under the influence of growth and in response to environment modifications are presented. The influence of carbon dioxide content during growth (normal or double percentage) was made clear

Incidence of cardiovascular events after kidney transplantation and cardiovascular risk scores: study protocol

<p>Abstract</p> <p>Background</p> <p>Cardiovascular disease (CVD) is the major cause of death after renal transplantation. Not only conventional CVD risk factors, but also transplant-specific risk factors can influence the development of CVD in kidney transplant recipients.</p> <p>The main objective of this study will be to determine the incidence of post-transplant CVD after renal transplantation and related factors. A secondary objective will be to examine the ability of standard cardiovascular risk scores (Framingham, Regicor, SCORE, and DORICA) to predict post-transplantation cardiovascular events in renal transplant recipients, and to develop a new score for predicting the risk of CVD after kidney transplantation.</p> <p>Methods/Design</p> <p>Observational prospective cohort study of all kidney transplant recipients in the A Coruña Hospital (Spain) in the period 1981-2008 (2059 transplants corresponding to 1794 patients).</p> <p>The variables included will be: donor and recipient characteristics, chronic kidney disease-related risk factors, pre-transplant and post-transplant cardiovascular risk factors, routine biochemistry, and immunosuppressive, antihypertensive and lipid-lowering treatment. The events studied in the follow-up will be: patient and graft survival, acute rejection episodes and cardiovascular events (myocardial infarction, invasive coronary artery therapy, cerebral vascular events, new-onset angina, congestive heart failure, rhythm disturbances and peripheral vascular disease).</p> <p>Four cardiovascular risk scores were calculated at the time of transplantation: the Framingham score, the European Systematic Coronary Risk Evaluation (SCORE) equation, and the REGICOR (Registre Gironí del COR (Gerona Heart Registry)), and DORICA (Dyslipidemia, Obesity, and Cardiovascular Risk) functions.</p> <p>The cumulative incidence of cardiovascular events will be analyzed by competing risk survival methods. The clinical relevance of different variables will be calculated using the ARR (Absolute Risk Reduction), RRR (Relative Risk Reduction) and NNT (Number Needed to Treat).</p> <p>The ability of different cardiovascular risk scores to predict cardiovascular events will be analyzed by using the c index and the area under ROC curves. Based on the competing risks analysis, a nomogram to predict the probability of cardiovascular events after kidney transplantation will be developed.</p> <p>Discussion</p> <p>This study will make it possible to determine the post-transplant incidence of cardiovascular events in a large cohort of renal transplant recipients in Spain, to confirm the relationship between traditional and transplant-specific cardiovascular risk factors and CVD, and to develop a score to predict the risk of CVD in these patients.</p

Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

End-stage kidney disease due to haemolytic uraemic syndrome - outcomes in 241 consecutive ANZDATA Registry cases

Extent: 11p.Background: The aim of this study was to investigate the characteristics and outcomes of patients receiving renal replacement therapy for end-stage kidney disease (ESKD) secondary to haemolytic uraemic syndrome (HUS). Methods: The study included all patients with ESKD who commenced renal replacement therapy in Australia and New Zealand between 15/5/1963 and 31/12/2010, using data from the ANZDATA Registry. HUS ESKD patients were compared with matched controls with an alternative primary renal disease using propensity scores based on age, gender and treatment era. Results: Of the 58422 patients included in the study, 241 (0.4%) had ESKD secondary to HUS. HUS ESKD was independently associated with younger age, female gender and European race. Compared with matched controls, HUS ESKD was not associated with mortality on renal replacement therapy (adjusted hazard ratio [HR] 1.14, 95% CI 0.87-1.50, p = 0.34) or dialysis (HR 1.34, 95% CI 0.93-1.93, p = 0.12), but did independently predict recovery of renal function (HR 54.01, 95% CI 1.45-11.1, p = 0.008). 130 (54%) HUS patients received 166 renal allografts. Overall renal allograft survival rates were significantly lower for patients with HUS ESKD at 1 year (73% vs 91%), 5 years (62% vs 85%) and 10 years (49% vs 73%). HUS ESKD was an independent predictor of renal allograft failure (HR 2.59, 95% CI 1.70-3.95, p < 0.001). Sixteen (12%) HUS patients experienced failure of 22 renal allografts due to recurrent HUS. HUS ESKD was not independently associated with the risk of death following renal transplantation (HR 0.92, 95% CI 0.35-2.44, p = 0.87). Conclusions: HUS is an uncommon cause of ESKD, which is associated with comparable patient survival on dialysis, an increased probability of renal function recovery, comparable patient survival post-renal transplant and a heightened risk of renal transplant graft failure compared with matched ESKD controls.Wen Tang, Janaki Mohandas, Stephen P McDonald, Carmel M Hawley, Sunil V Badve, Neil Boudville, Fiona G Brown, Philip A Clayton, Kathryn J Wiggins, Kym M Bannister, Scott B Campbell and David W Johnso

50-year return-period wet-snow load estimation based on weather station data for overhead line design in France

Historically, as far as wet-snow loads were concerned, overhead line design was often based on experience or long-term applications with positive results. New standard like CENELEC EN 50341-1 (2012) take into account characteristic loads, i.e. 50-year return-period loads, for the overhead line design. This article proposes a method to estimate characteristic wet-snow loads based on meteorological data recorded at weather stations. The model used to calculate those loads is mainly inspired by a recent article written by Nygaard et al. (2013a) in which a new parameterization is proposed for the classical cylindrical wet-snow accretion model, as described in ISO 12494 standard (2001), annex C. After a complete description of the model and its parameterization adapted to French wet-snow events, the statistical issues are examined. Then, the model is used with the meteorological data of 87 weather stations in order to calculate wet-snow loads whose relevance has been positively tested according to real damages recorded in a complete wet-snow event database. At last, the characteristic loads of those 87 stations have been determined according to all the loads generated by the model and processed by a peak-over-threshold (POT) method. A practical method to determine the 90% confidence intervals of those characteristic values is given. As it is demonstrated that there is only one value of the ice class (IC) masses proposed by ISO 12494 in each confidence interval, characteristic loads can be easily expressed in terms of ICs. That method shows that ICs ranging from R1 (0.5 kg m−1) to R5 (5 kg m−1) could be used for overhead line design in France

Estudio de las supuestas escorias y tierras cocidas de la serie pampeana de la República Argentina

Con el propósito de contribuir al conocimiento del verdadero origen de las «escorias» y «tierras cocidas», que tanto abundan en la serie pampeana, hemos emprendido el estudio de esos materiales, reuniendo todos los elementos que podían ilustrar el criterio del geólogo y del antropólogo, en la interesante cuestión tan debatida desde hace muchos años. La primera parte de esta memoria, comprende una breve reseña histórica de los diversos hallazgos hechos del material discutido, complementada con una revisión de las muestras conservadas en el Museo de La Plata y por las observaciones personales que uno de nosotros ha realizado en el terreno; además, se ha agregado un resumen de las diversas opiniones emitidas para explicar el origen probable de las «escorias» y «tierras cocidas». El estudio químico forma la segunda parte, y en el cual, para mejor inteligencia de los datos analíticos obtenidos, se han separado los materiales estudiados en cuatro grupos diferentes. En el primero se han considerado distintas muestras de loess, en las cuales se hallan incrustadas las «escorias» y «tierras cocidas»; en el segundo, se examinan estos materiales discutidos, habiendo elegido muestras tipos para su aná lisis completo; en el tercero, figuran todos los elementos de comparación, numerosos y heterogéneos, que se ha podido conseguir, así como también los ensayos practicados para producir «escorias» y «tierras cocidas»; y, en el cuarto grupo, se han reunido varias «toscas» como complemento del estudio.Facultad de Ciencias Naturales y Muse