Reutilizar purines de tambo como oportunidad para reciclar nitrógeno y reducir su impacto ambiental

Los purines de tambo (excretas mezcladas con agua de las instalaciones de ordeñe) se pueden reutilizar en la producción agrícola como reemplazo de los fertilizantes sintéticos. Sin embargo, su alta concentración nitrogenada podría estimular la volatilización de amoníaco (NH3 ) y la emisión de óxido nitroso (N2 O), con consecuencias sobre el calentamiento global. Nuestros objetivos fueron cuantificar las salidas de NH3 y N2 O en un cultivo de maíz fertilizado con purín o urea aplicados superficialmente y relacionar las emisiones de N2 O con los cambios en el contenido de amonio, nitrato y agua del suelo. Se realizó un experimento manipulativo a campo en el que se midieron ambas salidas gaseosas durante una campaña agrícola. El purín estimuló la volatilización de NH3 al día siguiente de la aplicación (2.7±0.25 vs. 1.1±0.25 y 0.6±0.25 kg N-NH3 .ha-1.dia-1 para purín, urea y control, respectivamente), y la emisión directa de N2 O durante los tres días siguientes a la aplicación (75±13 vs. 28±5 y 26±6 µg N-N2 O. m-2.h-1 para purín, urea y control, respectivamente). A partir del cuarto día, la volatilización de NH3 fue mayor con urea y las emisiones de N2 O se equipararon entre tratamientos. La volatilización acumulada durante el ciclo de maíz fue mayor con urea, y la emisión directa de N2 O acumulada fue similar para ambos fertilizantes. Las emisiones de N2 O estuvieron asociadas a la humedad del suelo, que aumentó inicialmente por el agua del purín y luego por las lluvias. Las salidas de NH3 +N2 O de los fertilizantes luego de descontar el control fueron mayores con urea que con purín (10.8±1.2 y 3.1±0.7 kg N/ha o 0.53±0.06 y 0.18±0.04 kg N/t MS), y el rendimiento de maíz fue similar entre tratamientos (19.0±0.7 t MS/ha). Estos resultados muestran que el uso de purines es una práctica promisoria para reducir el impacto ambiental de los fertilizantes sintéticos.Dairy cattle slurry (liquid mixture of manure and water from the milking operation) can be reused for agricultural production in replacement for synthetic fertilizers. However, its high nitrogen (N) concentration could stimulate the volatilization of ammonia (NH3) and nitrous oxide (N2O) emission, with consequences for global warming. Our objectives were: to quantify NH3 and N2O loss in maize fertilized with surface-applied dairy cattle slurry or urea, and to relate N2O emission with soil ammonium, nitrate and water contents. We performed a manipulative field experiment where we measured both gaseous losses during an agricultural campaign. Slurry enhanced NH3 volatilization the day after the application (2.7±0.25 vs. 1.1±0.25 and 0.6±0.25 kg N-NH3 .ha-1 .day-1 for slurry, urea and the control, respectively) and direct N2O emission during three days after the application (75±13 vs. 28±5 y 26±6 μg N-N2O .m-2 .h-1 for slurry, urea and the control, respectively). Four days after application, volatilization was higher with urea and N2O emissions were similar between treatments. The loss of NH3 accumulated throughout the maize growing season was higher for urea than for slurry, and the accumulated N2O emission was similar for both fertilizers. Nitrous oxide emissions were related to soil water content, initially introduced with slurry and then with rainfall. The loss of NH3+N2O from the fertilizers after subtracting that of the control, was higher after the application of urea than slurry (10.8±1.2 and 3.1±0.7 kg N/ha or 0.53±0.06 and 0.18±0.04 kg N/t MS), and maize yield was similar for both fertilization treatments (19.0±0.7 t MS/ha). These results show that fertilization with dairy cattle slurry is a promising practice because it has a lower environmental footprint compared to synthetic fertilizers.EEA PergaminoFil: Portela, Silvina Isabel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Laboratorio de Suelos; ArgentinaFil: Araujo, Patricia Inés. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Laboratorio de Suelo; ArgentinaFil: Araujo, Patricia Inés. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Restovich, Silvina B. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Laboratorio de Suelos; ArgentinaFil: Della Chiesa, Tomas. Universidad de Buenos Aires. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Della Chiesa, Tomas. Universidad de Buenos Aires. Facultad de Agronomía. Catedra de Climatología y Fenología Agrícolas; ArgentinaFil: Ponsa, Juliana M. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Escuela de Ciencias Agrarias, Naturales y Ambientales; ArgentinaFil: Peña Ballesteros, Andrea. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Escuela de Ciencias Agrarias, Naturales y Ambientales; Argentin

Monitoreo de un sistema de lagunas de tratamiento de efluente de tambo

El manejo de las excretas y el agua es fundamental en la sustentabilidad ambiental de los sistemas de producción de leche. El vertido de efluentes crudos o deficientemente tratados a cursos de agua o al suelo es frecuente y puede resultar en situaciones contaminantes por acumulación o transferencia de nutrientes. El objetivo fue evaluar la eficiencia depuradora de un sistema de lagunas de tratamiento y la variación estacional de la composición del efluente de tambo.EEA PergaminoFil: Portela, Silvina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Laboratorio Suelo; ArgentinaFil: Torti, María Juliana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Laboratorio Calidad de Alimento, Suelos y Agua; ArgentinaFil: Garbini, Dalila J. Universidad Nacional del Noroeste de la Provincia de Buenos Aires (UNNOBA). Escuela de Ciencias Agrarias, Naturales y Ambientales; ArgentinaFil: Cabrini, Silvina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Economía; ArgentinaFil: Araujo, Patricia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Laboratorio de Suelos; ArgentinaFil: Restovich, Silvina Beatríz. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Laboratorio de Suelos; Argentin

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

Higher than expected N2O emissions from soybean crops in the Pampas Region of Argentina: Estimates from DayCent simulations and field measurements

In developing countries, agriculture generally represents a large fraction of GHG emissions reported in National Inventories, and emissions are typically estimated using Tier 1 IPCC guidelines. However, field data and locally adapted simulation models can improve the accuracy of IPCC estimations. In this study we aimed to quantify anthropogenic N2O emissions from croplands of Argentina through field measurements, model simulations and IPCC guidelines. We measured N2O emissions and their controlling factors in 62 plots of the Pampas Region with corn, soybean and wheat/soybean crops and in unmanaged grasslands. We accounted for gross emissions from crops and background emissions from unmanaged grasslands to calculate net anthropogenic emissions from crops as the difference between them. We calibrated and evaluated the DayCent model and then simulated different weather and management scenarios. Finally, we applied IPCC guidelines to estimate anthropogenic N2O emissions at the same plots. The DayCent model accurately simulated annual N2O emission for all crops as compared to measured data (RMSE = 1.4 g N ha−1 day−1). Measured and simulated emissions in soybean crops were higher than in corn and wheat/soybean crops. Gross N2O emissions ranged from 1.4 to 5.1 kg N ha−1 yr−1 for current environmental (soil and weather) and management (crops and fertilizer doses) conditions. Background emissions ranged between 1.1 and 1.3 kg N ha−1 yr−1, and therefore net anthropogenic emissions ranged from 0.3 to 4.0 kg N ha−1 yr−1. IPCC Tier 1 emission factors underestimated N2O releases from soybean, that were on average 4.87 times greater when estimated with DayCent and observations (0.53 vs 2.47 and 2.69 kg N ha−1 yr−1, respectively). On the contrary, IPCC estimates for corn and wheat/soybean crops were similar to modeled and measured values. Our results suggest that N2O emissions from the vast 15 million ha of soybean croplands in the Pampas Region may be substantially underestimated.EEA PergaminoFil: Della Chiesa, Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires (CONICET-UBA). Instituto de Investigaciones Fisiológicas y Ecológicas vinculadas a la Agricultura (IFEVA); ArgentinaFil: Della Chiesa, Tomas. Universidad de Buenos Aires. Facultad de Agronomía. Catedra de Climatología y Fenología Agrícolas; ArgentinaFil: Piñeiro, Gervasio. Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires (CONICET-UBA). Instituto de Investigaciones Fisiológicas y Ecológicas vinculadas a la Agricultura (IFEVA); ArgentinaFil: Piñeiro, Gervasio. Universidad de Buenos Aires. Facultad de Agronomía. Laboratorio de Análisis Regional y Teledetección; ArgentinaFil: Piñeiro, Gervasio. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente. Catedra de Ecología; ArgentinaFil: Del Grosso, Stephen J. USDA-ARS. Soil Management and Sugar Beet Research Unit; Estados UnidosFil: Parton, William J. Colorado State University. Natural Resource Ecology Laboratory; Estados UnidosFil: Araujo, Patricia Inés. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Laboratorio de Suelo; ArgentinaFil: Araujo, Patricia Inés. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Yahdjian, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires (CONICET-UBA). Instituto de Investigaciones Fisiológicas y Ecológicas vinculadas a la Agricultura (IFEVA); ArgentinaFil: Yahdjian, Laura. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente. Catedra de Ecología; Argentin

Nitric Oxide Stimulates the Proliferation of Neural Stem Cells Bypassing the Epidermal Growth Factor Receptor

Nitric oxide (NO) was described to inhibit the proliferation of neural stem cells. Some evidence suggests that NO, under certain conditions, can also promote cell proliferation, although the mechanisms responsible for a potential proliferative effect of NO in neural stem cells have remained unaddressed. In this work, we investigated and characterized the proliferative effect of NO in cell cultures obtained from the mouse subventricular zone. We found that the NO donor NOC-18 (10 mu M) increased cell proliferation, whereas higher concentrations (100 mu M) inhibited cell proliferation. Increased cell proliferation was detected rapidly following exposure to NO and was prevented by blocking the mitogen-activated kinase (MAPK) pathway, independently of the epidermal growth factor (EGF) receptor. Downstream of the EGF receptor, NO activated p21Ras and the MAPK pathway, resulting in a decrease in the nuclear presence of the cyclin-dependent kinase inhibitor I, p27(KIP1), allowing for cell cycle progression. Furthermore, in a mouse model that shows increased proliferation of neural stem cells in the hippocampus following seizure injury, we observed that the absence of inducible nitric oxide synthase (iNOS(-/-) mice) prevented the increase in cell proliferation observed following seizures in wild-type mice, showing that NO from iNOS origin is important for increased cell proliferation following a brain insult. Overall, we show that NO is able to stimulate the proliferation of neural stem cells bypassing the EGF receptor and promoting cell division. Moreover, under pathophysiological conditions in vivo, NO from iNOS origin also promotes proliferation in the hippocampus. STEM CELLS 2010:28:1219-123

Characterization of GASA-1, a new vaccine candidate antigen of Babesia bovis

Surface proteins bound to the cell membrane by glycosylphosphatidylinositol (GPI) anchors are considered essential for the survival of pathogenic protozoans. In the case of the tick-transmitted hemoparasite Babesia bovis, the most virulent causative agent of bovine babesiosis, the GPI-anchored proteome was recently unraveled by an in silico approach. In this work, one of the identified proteins, GASA-1 (GPI-Anchored Surface Antigen-1), was thoroughly characterized. GASA-1 is 179 aa long and has the characteristic features of a GPI-anchored protein, including a signal peptide, a hydrophilic core and a hydrophobic tail that harbors a GPI anchor signal. Transcriptomic analysis shows that it is expressed in pathogenic and attenuated B. bovis strains. Notably, the gasa-1 gene has syntenic counterparts in B. bigemina and B. ovata, which also encode GPI-anchored proteins. This is highly unusual since all piroplasmid GPI-anchored proteins described so far have been found to be species-specific. Sequencing of gasa-1 alleles from B. bovis geographical isolates originating from Argentina, USA, Brazil, Mexico and Australia showed over 98 % identity in both nucleotide and amino acid sequences. A recombinant form of GASA-1 (rGASA-1) was generated in E. coli and anti-rGASA-1 antibodies were raised in mice. Fixed and live immunofluorescence assays showed that GASA-1 is expressed in in vitro cultured B. bovis merozoites and surface-exposed. Moreover, incubation of B. bovis in vitro cultures with anti-GASA-1 antibodies partially, but significantly, reduced erythrocyte invasion, indicating that this protein bears neutralization-sensitive antibody epitopes. Splenocytes of rGASA-1-inoculated mice showed a specific proliferative response when exposed to the recombinant protein, indicating that GASA-1 bears T-cell epitopes. Finally, sera from a group of B. bovis-infected cattle reacted with the recombinant protein, demonstrating that GASA-1 is expressed during natural infection of bovines with B. bovis, and suggesting that it is immunodominant. The high degree of conservation among B. bovis isolates and the presence of syntenic genes in other Babesia species suggest a relevant role of GASA-1 and GASA-1-like proteins for parasite survival, especially considering that, due to their surface location, they are exposed to the selection pressure of the host immune system. The highlighted features of GASA-1 make it an interesting candidate for the development of vaccines against bovine babesiosis.Instituto de PatobiologíaFil: Flores, Daniela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología; ArgentinaFil: Rodriguez, Anabel Elisa. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología; ArgentinaFil: Tomazic, Mariela Luján. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología; ArgentinaFil: Torioni, Susana Marta. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Echaide, Ignacio Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Zamorano, Patricia Ines. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; ArgentinaFil: Langellotti, Cecilia Ana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; ArgentinaFil: Araujo, Flabio Ribeiro de. Empresa Brasileira de Pesquisa Agropecuária (Embrapa). Gado de Corte; BrasilFil: Rolls, Peter. Tick Fever Centre. Department of Agriculture & Fisheries; AustraliaFil: Schnittger, Leonhard. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología; ArgentinaFil: Florin-Christensen, Monica. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología; ArgentinaFil: Flores, Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); ArgentinaFil: Tomazic, Mariela Luján. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); ArgentinaFil: Schnittger, Leonhard. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); ArgentinaFil: Florin-Christensen, Monica. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentin