Mejoramiento en avena: resistencia genética a pulgón

La avena, con una superficie sembrada estimada en 1.400.000 ha, se utiliza como integrante de mezclas forrajeras o verdeos, modalidad de uso que representa más del 70% de dicha superficie. El pulgón verde , schizaphis graminum (rond), la plaga de mayor incidencia en los cereales de invierno, afecta especialmente siembras tempranas de verdeo, tal como ocurre en avena. El control de este áfido es posible mediante el logro de variedades con resistencia genética, la utilización de dichas variedades, disminuye notablemente las pérdidas de producción, resulta compatible con otras estrategias de control biológico, cultural e incluso químico. Simplifica el manejo, reduce costos y resulta acorde con los actuales criterios de sustentabilidad: sistemas productivos de bajos insumos, que limiten el impacto ambiental. Objetivo: obtención de cultivares con resistencia genética al pulgón verde, que incluyan además cualidades agronómicas, como rendimiento en pasto y en grano, sanidad y calidad

Mejoramiento en avena: resistencia genética a pulgón

La avena, con una superficie sembrada estimada en 1.400.000 ha, se utiliza como integrante de mezclas forrajeras o verdeos, modalidad de uso que representa más del 70% de dicha superficie. El pulgón verde , schizaphis graminum (rond), la plaga de mayor incidencia en los cereales de invierno, afecta especialmente siembras tempranas de verdeo, tal como ocurre en avena. El control de este áfido es posible mediante el logro de variedades con resistencia genética, la utilización de dichas variedades, disminuye notablemente las pérdidas de producción, resulta compatible con otras estrategias de control biológico, cultural e incluso químico. Simplifica el manejo, reduce costos y resulta acorde con los actuales criterios de sustentabilidad: sistemas productivos de bajos insumos, que limiten el impacto ambiental. Objetivo: obtención de cultivares con resistencia genética al pulgón verde, que incluyan además cualidades agronómicas, como rendimiento en pasto y en grano, sanidad y calidad.Facultad de Ciencias Agrarias y Forestale

Local sclerotherapy with Polydocanol (Aethoxysklerol®) for the treatment of Epistaxis in Rendu-Osler-Weber or Hereditary Hemorrhagic Telangiectasia (HHT): 15 years of experience*

Producción CientíficaHereditary Haemorrhagic Telangiectasia or Rendu-Osler-Weber syndrome is a rare autosomal dominant vascular disease characterized by mucocutaneous and gastrointestinal telangiectases and localized arteriovenous malformations in lung, brain and liver. Epistaxis, due to rupture of telangiectases of the nasal mucosa, is the most frequent clinical manifestation, leading in many cases to severe impairment of the quality of life in the patients. Though several treatments have been used to reduce epistaxis, none have been completely effective, with the exception of polydocanol (Aethoxysklerol®) in submucosal or subpericondrial injections, which was first presented in 2000 with very good results. After fifteen years using polydocanol in submucosal injections on 45 patients and with nearly 300 injections, we have observed that in 95% of all cases, their nose bleeds improved with respect to frequency and quantity without any important side effects. There was just one case of septal perforation, another with increased septal perforation, and one patient who suffered from dizziness and blurred vision for a few minutes. In this paper the results obtained using this technique over a fifteen-year period will be presented and evaluated

Additive Manufacturing for the Rapid Prototyping of Economical Biosensors

Current methods of developing wearable electronics through reductive manufacturing pose a substantial ecological footprint. To address this issue, it is imperative to investigate alternative additive manufacturing techniques. Aerosol jet printing (AJP) is a promising approach that relies on the optimization of gas flow rates and ink rheology to produce high-resolution printed structures. Implementing a low-intensity layered delamination approach to synthesize titanium carbide MXene, and further produce MXene ink, reduces environmental impact while enhancing the device performance. MXene ink yields desirable rheology, including viscosity, surface tension, density, and contact angles compatible with AJP technique. In terms of cost, ecological effect, time, and process development, traditional manufacturing exacerbates the level of e-waste produced. However, this additive manufacturing technique offers a unique solution for rapidly prototyping and manufacturing economical biosensors while minimizing resource consumption, reducing environmental impact, and addressing the growing issue of e-waste

Stellar 36,38^{36,38}Ar(n,γ)37,39(n,\gamma)^{37,39}Ar reactions and their effect on light neutron-rich nuclide synthesis

The $^{36}$Ar$(n,\gamma)^{37}$Ar ($t_{1/2}$ = 35 d) and $^{38}$Ar$(n,\gamma)^{39}$Ar (269 y) reactions were studied for the first time with a quasi-Maxwellian ($kT \sim 47$ keV) neutron flux for Maxwellian Average Cross Section (MACS) measurements at stellar energies. Gas samples were irradiated at the high-intensity Soreq applied research accelerator facility-liquid-lithium target neutron source and the $^{37}$Ar/$^{36}$Ar and $^{39}$Ar/$^{38}$Ar ratios in the activated samples were determined by accelerator mass spectrometry at the ATLAS facility (Argonne National Laboratory). The $^{37}$Ar activity was also measured by low-level counting at the University of Bern. Experimental MACS of $^{36}$Ar and $^{38}$Ar, corrected to the standard 30 keV thermal energy, are 1.9(3) mb and 1.3(2) mb, respectively, differing from the theoretical and evaluated values published to date by up to an order of magnitude. The neutron capture cross sections of $^{36,38}$Ar are relevant to the stellar nucleosynthesis of light neutron-rich nuclides; the two experimental values are shown to affect the calculated mass fraction of nuclides in the region A=36-48 during the weak $s$-process. The new production cross sections have implications also for the use of $^{37}$Ar and $^{39}$Ar as environmental tracers in the atmosphere and hydrosphere.Comment: 18 pages + Supp. Mat. (13 pages) Accepted for publication in Phys. Rev. Let

Polyphenolic composition of Lantana camara and Lippia chevalieri, and their Antioxidant and Antimicrobial Activities

In the present study, the antioxidant and antibacterial activities of methanolic extracts of two Verbenaceae (Lantana camara L. and Lippia chevalieri Moldenke: aerial part) were investigated. Their polyphenolic composition in the ethyl acetate and aqueous fractions were characterized by HPLC-DAD. The antioxidant capability of the methanolic extracts was assessed by the Ferric Reducing Antioxidant Power (FRAP) and the scavenging activity of the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). The Minimum Inhibitory Concentrations (MIC) of the methanolic extracts (25 µg mL-1), and the minimum bactericidal concentrations (MBC) (12.5 µg mL-1) against 13 pathogenic bacteria and four serotyped bacteria from the American Type Culture Collection (ATCC) were also determined by the agar-well diffusion method. The results indicated that the L. chevalieri extracts are rich in phenolic compounds (among the 27 polyphenolic compounds detected, 20 belong to L. chevalieri) and showed the highest antioxidant activities, simultaneously on iron (III) to iron (II)-reducing activity and the radical scavenging activity. However, L. camara displayed the best and the broadest antimicrobial spectrum, especially on Shigella flexneri and Pantoea sp. (two Gram-negative strains of bacteria). The nature of polyphenolics compounds detected (phenol acid and flavone) in the L. camara can justify this activity.Key words: Verbenaceae, HPLC-DAD, antioxidant activity, antimicrobial activity, polyphenolic compound

Independent measurement of the Hoyle state β\beta feeding from 12B using Gammasphere

Using an array of high-purity Compton-suppressed germanium detectors, we performed an independent measurement of the $\beta$-decay branching ratio from $^{12}\mathrm{B}$ to the second-excited (Hoyle) state in $^{12}\mathrm{C}$. Our result is $0.64(11)\%$, which is a factor $\sim 2$ smaller than the previously established literature value, but is in agreement with another recent measurement. This could indicate that the Hoyle state is more clustered than previously believed. The angular correlation of the Hoyle state $\gamma$ cascade has also been measured for the first time. It is consistent with theoretical predictions

The first direct measurement of ¹²C (¹²C,n) ²³Mg at stellar energies

Neutrons produced by the carbon fusion reaction ¹²C(¹²C,n)²³Mg play an important role in stellar nucleosynthesis. However, past studies have shown large discrepancies between experimental data and theory, leading to an uncertain cross section extrapolation at astrophysical energies. We present the first direct measurement that extends deep into the astrophysical energy range along with a new and improved extrapolation technique based on experimental data from the mirror reaction ¹²C(¹²C,p)²³Na. The new reaction rate has been determined with a well-defined uncertainty that exceeds the precision required by astrophysics models. Using our constrained rate, we find that ¹²C(¹²C,n)²³Mg is crucial to the production of Na and Al in Pop-III Pair Instability Supernovae. It also plays a non-negligible role in the production of weak s-process elements as well as in the production of the important galacti

A compactness theorem for scalar-flat metrics on manifolds with boundary

Let (M,g) be a compact Riemannian manifold with boundary. This paper is concerned with the set of scalar-flat metrics which are in the conformal class of g and have the boundary as a constant mean curvature hypersurface. We prove that this set is compact for dimensions greater than or equal to 7 under the generic condition that the trace-free 2nd fundamental form of the boundary is nonzero everywhere.Comment: 49 pages. Final version, to appear in Calc. Var. Partial Differential Equation