Comparison of nitrification inhibitors to restrict nitrate leaching in a maize crop irrigated under mediterranean conditions

The aim of this paper was to compare dicyandiamide (DCD) and 3,4 dimethylpyrazole phosphate (DMPP) as inhibitors of ammonium oxidation and nitrate leaching after applying fertilizer to a maize (Zea mays L.) crop grown under Mediterranean conditions. The effects of nitrification inhibitors were also compared to those of N fertilization without inhibitors and with split N application. In plots fertilized with ammonium sulphate nitrate (ASN), either DCD or DMPP lengthened ammonium presence in soil and produced lower soil NO3- concentrations (30% lower than in plots with no inhibitor). The use of DCD or DMPP achieved significant reductions in nitrate leaching. DCD showed excellent properties for controlling nitrate leaching, taking into account the fact that grain yield and N accumulated by plant were similar for the ASN-DCD and ASN treatments applied at the same N doses. The split N treatment did not offer any advantages in terms of leached nitrate, either with the use of single ammonium sulphate nitrate (ASN) or with single application of nitrification inhibitors. The nitrification inhibitors did not increase the yield but did not reduce it either. The drainage rate was the most important component of nitrate leaching. The low drainage values of the first year resulted in a sharp decline of nitrate leaching. However, the experiment of the second year, showed clear differences in nitrate leaching between treatments due to the greater drainage

Ischemic postconditioning reduces reperfusion arrhythmias by adenosine receptors and protein kinase C activation but is independent of KATP channels or connexin 43

Funding: This study was supported by Secretaría de Investigación, Internacionales y Posgrado, Universidad Nacional de Cuyo (06/J505) and by the Spanish, Ministerio de Ciencia, Innovación y Universidades, Instituto de Salud Carlos III (CIBERCV), cofinanced by the European Regional Development Fund (ERDF-FEDER, a way to build Europe), and by Fundació La Marató de TV3 (n◦. 201536-10). Antonio Rodríguez-Sinovas has a consolidated Miguel Servet contract. Jose A. Sánchez was supported by the International Research Training Group 1566 on Protecting the Heart from Ischemia (PROMISE).Ischemic postconditioning (IPoC) reduces reperfusion arrhythmias but the antiarrhythmic mechanisms remain unknown. The aim of this study was to analyze IPoC electrophysiological effects and the role played by adenosine A, A and A receptors, protein kinase C, ATP-dependent potassium (K) channels, and connexin 43. IPoC reduced reperfusion arrhythmias (mainly sustained ventricular fibrillation) in isolated rat hearts, an effect associated with a transient delay in epicardial electrical activation, and with action potential shortening. Electrical impedance measurements and Lucifer-Yellow diffusion assays agreed with such activation delay. However, this delay persisted during IPoC in isolated mouse hearts in which connexin 43 was replaced by connexin 32 and in mice with conditional deletion of connexin 43. Adenosine A, A and A receptor blockade antagonized the antiarrhythmic effect of IPoC and the associated action potential shortening, whereas exogenous adenosine reduced reperfusion arrhythmias and shortened action potential duration. Protein kinase C inhibition by chelerythrine abolished the protective effect of IPoC but did not modify the effects on action potential duration. On the other hand, glibenclamide, a K inhibitor, antagonized the action potential shortening but did not interfere with the antiarrhythmic effect. The antiarrhythmic mechanisms of IPoC involve adenosine receptor activation and are associated with action potential shortening. However, this action potential shortening is not essential for protection, as it persisted during protein kinase C inhibition, a maneuver that abolished IPoC protection. Furthermore, glibenclamide induced the opposite effects. In addition, IPoC delays electrical activation and electrical impedance recovery during reperfusion, but these effects are independent of connexin 43

Potential control of forest diseases by solutions of chitosan oligomers, propolis and nanosilver

There is a growing necessity to replace chemical agents with ecofriendly materials, arising from the impact on the environment and/or human health, which calls for the design of new broad-spectrum fungicides. In this work, chitosan oligomers (COs), propolis (Ps) and silver nanoparticles (AgNPs) mixtures in solution were assessed to control the growth of different phytopathogenic fungi and oomycetes in vitro. Binary solutions of COs-Ps and COs-AgNPs evinced the highest antifungal effect against Fusarium circinatum and Diplodia pinea fungi, respectively, with a ca. 80% reduction in their mycelial growth. The COs solution by itself also proved to be greatly effective against Gremmeniella abietina, Cryphonectria parasitica and Heterobasidion annosum fungi, causing a reduction of 78%, 86% and 93% in their growth rate, respectively. Likewise, COs also attained a 100% growth inhibition on the oomycete Phytophthora cambivora. On the other hand, Ps inhibited totally the growth of Phytophthora ×alni and Phytophthora plurivora. The application of AgNPs reduced the mycelial growth of F. circinatum and D. pinea. However, the AgNPs in some binary and ternary mixtures had a counter-productive effect on the anti-fungal/oomycete activity. In spite of the fact that the anti-fungal/oomycete activity of the different treatments showed a dependence on the particular type of microorganism, these solutions based on natural compounds can be deemed as a promising tool for control of tree diseases

Revisión de la obra de Antonio Bisquert en la ciudad de Teruel a través de su análisis radiográfico y caracterización de materiales mediante SEM/EDX

El presente trabajo de investigación, con un claro carácter interdisciplinar, se focaliza en un estudio donde se han combinado datos histórico-artísticos junto a una extensa documentación radiográfica, más un amplio estudio estratigráfico y químico mediante Microscopía óptica y Microscopia electrónica de barrido. Todo ello sobre un conjunto de ocho lienzos de la producción artística del pintor Antonio Bisquert en la ciudad de Teruel. Las obras analizadas en este artículo se encuentran localizadas tanto en el Museo de Arte Sacro de Teruel, como en diferentes iglesias de esa misma localidad. Tanto los resultados obtenidos de las imágenes radiográficas como los que ofrecen las pruebas analíticas conforman un compendio inédito de lo que se refleja en todo el proceso creativo y su génesis, revelando atribuciones contrastadas y el empleo de posteriores retoques considerados como no originales, que fueron ejecutados por una misma mano en una misma época. Todos estos datos generan un gran interés para el reconocimiento y puesta en valor de la obra de este olvidado pintor. The present research work, with an interdisciplinary character, focuses on a study where historical-artistic data were combined with extensive radiographic documentation and extensive stratigraphic and chemical studies using optical microscopy and scanning electron microscopy. All this on a set of eight canvases of the artistic work''s Antonio Bisquert in the city of Teruel. These works are located in the Museum of Sacred Art of Teruel and in different churches of this area. The results show a compendium of radiographic unpublished images, which reflects the entire creative process and the genesis of the works, revealing contrasted attributions and the use of subsequent retouchings considered not original, which were executed by the same hand at the same time. All these data generate a great interest for the recognition and the development of forgotten the artist''s output

Ammonia emissions from a soil amended with urea and inhibitor of urease activity in a Mediterranean area

Urea and ammonium-based fertilisers are nowadays one of the most important sources of ammonia (NH3) emissions to the atmosphere in Europe. However, little is known about NH3 volatilisation in Mediterranean areas. The aim of the present study was the quantification of NH3 emissions by using the Integrated Horizontal Flux (IHF) method after application of urea with the urease inhibitor N-(n-butyl) thiophosphorie triamide (NBPT) to a semiarid agricultural soil. The field experiment was carried out at "La Poveda" field station in Madrid on a sunflower crop in spring 2006. Urea and a mixture of urea and the inhibitor (0.14%) were surfaee-applied by hand at a rate of 170 kg N ha"' to eircular plots (diam. 40 m). The soil was irrigated with 10 mm of water just after the applieation of urea to dissolve and incorporate it onto the first layer of soil. There were three peaks in the NH3 flux over the duration of the measurement period (36 d). The first peak was associated to irrigation and the others to rainfall events. The total NH3 emission during the whole experiment (36 days) was 17.3 ±5.5kgNH3-N ha"1 in the ease of urea treated soils and 10.0 ± 4.5 kg NHrN ha"' where NBPT was ineluded with the urea

Towards a formal description of the collapse approach to the inflationary origin of the seeds of cosmic structure

Inflation plays a central role in our current understanding of the universe. According to the standard viewpoint, the homogeneous and isotropic mode of the inflaton field drove an early phase of nearly exponential expansion of the universe, while the quantum fluctuations (uncertainties) of the other modes gave rise to the seeds of cosmic structure. However, if we accept that the accelerated expansion led the universe into an essentially homogeneous and isotropic space-time, with the state of all the matter fields in their vacuum (except for the zero mode of the inflaton field), we can not escape the conclusion that the state of the universe as a whole would remain always homogeneous and isotropic. It was recently proposed in [A. Perez, H. Sahlmann and D. Sudarsky, "On the quantum origin of the seeds of cosmic structure," Class. Quant. Grav. 23, 2317-2354 (2006)] that a collapse (representing physics beyond the established paradigm, and presumably associated with a quantum-gravity effect a la Penrose) of the state function of the inflaton field might be the missing element, and thus would be responsible for the emergence of the primordial inhomogeneities. Here we will discuss a formalism that relies strongly on quantum field theory on curved space-times, and within which we can implement a detailed description of such a process. The picture that emerges clarifies many aspects of the problem, and is conceptually quite transparent. Nonetheless, we will find that the results lead us to argue that the resulting picture is not fully compatible with a purely geometric description of space-time.Comment: 53 pages, no figures. Revision to match the published versio

Preliminary characterisation of the promoter of the human p22phox gene: identification of a new polymorphism associated with hypertension

The p22(phox) subunit is an essential protein in the activation of NAD(P)H oxidase. Here we report the preliminary characterisation of the human p22(phox) gene promoter. The p22(phox) promoter contains TATA and CCAC boxes and Sp1, gamma-interferon and nuclear factor kappaB sites. We screened for mutations in the p22(phox) promoter and identified a new polymorphism, localised at position -930 from the ATG codon, which was associated with hypertension. Mutagenesis experiments showed that the G allele had higher promoter activity than the A allele. These results suggest that the -930(A/G) polymorphism in the p22(phox) promoter may be a novel genetic marker associated with hypertension

Phagocytic NADPH oxidase-dependent superoxide production stimulates matrix metalloproteinase-9: implications for human atherosclerosis

OBJECTIVE: Data suggest that matrix metalloproteinase-9 (MMP-9) has a role in atherosclerosis. The phagocytic NADPH oxidase has been also associated with atherosclerosis. This study aimed to investigate the association between phagocytic NADPH oxidase and MMP-9 in human atherosclerosis. METHODS AND RESULTS: In vitro experiments performed in human monocytes showed that NADPH oxidase activation enhanced MMP-9 secretion and activity, determined by enzyme-linked immunosorbent assay and zymography, respectively. Immunohistochemical study showed that phagocytic NADPH oxidase localized with MMP-9 in endarterectomies from patients with carotid stenosis. In addition, a positive relationship (P<0.001) was found between phagocytic NADPH oxidase-dependent superoxide production determined with lucigenin and plasma MMP-9 levels in 188 asymptomatic subjects free of overt clinical atherosclerosis. In multivariate analysis, this association remained significant after adjustment for cardiovascular risk factors. Interestingly, subjects in the upper quartile of superoxide production exhibited the highest values of MMP-9, oxidized low-density lipoprotein, nitrotyrosine, carotid intima media thickness, and an increased presence of carotid plaques. CONCLUSIONS: Enhanced NADPH oxidase-dependent *O2(-) production stimulates MMP-9 in monocytes and this relationship may be relevant in the atherosclerotic process. Moreover, MMP-9 emerges as an important mediator of the phagocytic NADPH oxidase-dependent oxidative stress in atherosclerosis