On the exciton model for ion-beam damage: The example of TiO2

The non-radiative exciton decay model recently developed to account for swift-ion-beam damage to LiNbO3 is, here, discussed within a general physical perspective, taking previous work on alkali halides as a reference. Some general rules for the validity of excitonic models have been put forward, allowing one to predict the irradiation behaviour of other materials. As a new example of application, some preliminary data on the generation and growth of uniform amorphous layers induced by irradiation with Br at 13 MeV and 25 MeV have been performed on rutile (TiO2). In addition sub-threshold irradiations with Br ions at 9 MeV have been carried out. Defects generation is observed as a result. This effect is explained with the exciton model. Experiments are in the electronic excitation regime and use moderate fluences in the range of 6 × 1012 to 1.5 × 1014 cm−2. The results show similar features to those found for LiNbO3 and are, in principle, consistent with a non-radiative exciton decay model

Control del mal de los almácigos causado por Rhizoctonia solani y Sclerotium rolfsii con caldos de cebolla

Damping off is a frequent disease that kills seedlings. Cultural control is the only tool in organic crops to manage this disease, and only empirical information is available on the efficiency of plant preparations. This work evaluates the effects of fermented onion decoctions on the growth of Rhizoctonia solani and Sclerotium rolfsii and disease incidence. Broth (B) and sterilized broth (SB) were respectively obtained by boiling chopped yellow onions in water, and incubating for 14 days at room temperature, with or without subsequent sterilization. The pathogens were grown on PDA supplemented with B and SB at 1.7, 3.3, 8.3, 16.7 and 25% (v/v). Their growth was reduced by B at 8.3, 16.7 and 25%. Production of sclerotia by S. rolfsii was diminished by B, but stimulated by SB. Penicillium purpurogenum, P. simplicissimum and Aspergillus niger obtained from B behaved as antagonistic against both pathogens, showing antibiosis, competition and hyperparasitism in dual confrontations with them. Broth and SB at 10 and 50% were sprayed on chard (Beta vulgaris), tomato (Solanum lycopersicum), pepper (Capsicum annuum) and eggplant (Solanum melongena) seedlings cultivated in pathogen-colonized soil. Damping off incidence in B treatments at 50% was markedly lower than the observed for SB. It is concluded that B antifungal activity depends on its dilution and mycota. Broth sprays should be considered as a tool to control damping off in low-environment-impact crop production. Further studies are needed for a complete understanding of B chemical and microbiological components, as well as their changes during fermentation.El mal de los almácigos causa muerte de plántulas. Los controles cultural y biológico constituyen las únicas herramientas orgánicas para su manejo. Acerca de la eficiencia de preparaciones vegetales, sólo se encuentra información de divulgación. Este trabajo evalúa el efecto de caldos fermentados de cebolla sobre el crecimiento de Rhizoctonia solani y Sclerotium rolfsii y la incidencia de la enfermedad. Se obtuvieron caldo (B) y caldo esterilizado (SB), respectivamente, mediante hervido de trozos de cebollas y fermentación a temperatura ambiente, con o sin esterilización posterior. Se cultivaron los patógenos en APG suplementado con B y SB diluidos 1,7; 3,3; 8,3; 16,7 y 25%. Su crecimiento decreció con B al 8,3, 16,7 y 25%. La producción de esclerocios por S. rolfsii disminuyó con B, pero aumentó con SB. Penicillium purpurogenum, P. simplicissimum y Aspergillus niger aislados de B evidenciaron antibiosis, competencia e hiperparasitismo respecto de ambos patógenos. B y SB diluidos 10 y 50% fueron aplicados en almácigos de acelga (Beta vulgaris), tomate (Solanum lycopersicum), pimiento (Capsicum annuum) y berenjena (Solanum melongena) infestados. La pérdida de plántulas fue menor en el tratamiento con B al 50%, en relación al tratamiento con SB. Se concluye que la actividad antifúngica de B depende de su dilución y de su micota. La utilización de caldos de cebolla debería ser contemplada como alternativa para el manejo fitosanitario de bajo impacto ambiental. Se requiere continuar los estudios para completar el conocimiento acerca de los componentes químicos y microbiológicos de los caldos, y sus posibles cambios durante la fermentación.Fil: Rivera, Marta Carolina. Universidad de Buenos Aires. Facultad de Agronomia; ArgentinaFil: Wright, Eduardo Roberto. Universidad de Buenos Aires. Facultad de Agronomia; ArgentinaFil: Fabrizio, Maria del Carmen. Universidad de Buenos Aires. Facultad de Agronomia; ArgentinaFil: Freixá, G.. Universidad de Buenos Aires. Facultad de Agronomia; ArgentinaFil: Cabalini, R.. Universidad de Buenos Aires. Facultad de Agronomia; ArgentinaFil: Lopez, Silvia Edith. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Compositional, structural and morphological modifications of N-rich Cu3N films induced by irradiation with Cu at 42 MeV

N-rich Cu3N films were irradiated with Cu at 42 MeV in the fluences range from 4 × 1011 to 1 × 1014 cm−2. The radiation-induced changes in the chemical composition, structural phases, surface morphology and optical properties have been characterized as a function of ion fluence, substrate temperature and angle of incidence of the incoming ion by means of ion-beam analysis (IBA), x-ray diffraction, atomic force microscopy, profilometry and Fourier transform infrared spectroscopy techniques. IBA methods reveal a very efficient sputtering of N whose yield (5 × 103 atom/ion) is almost independent of substrate temperature (RT-300 °C) but slightly depends on the incidence angle of the incoming ion. The Cu content remains essentially constant within the investigated fluence range. All data suggest an electronic mechanism to be responsible for the N depletion. The release of nitrogen and the formation of Cu2O and metallic Cu are discussed on the basis of existing models

The Atacama Cosmology Telescope: CO(J = 3 - 2) mapping and lens modeling of an ACT-selected dusty star-forming galaxy

We report Northern Extended Millimeter Array (NOEMA) CO($J = 3 - 2$) observations of the dusty star-forming galaxy ACT-S\,J020941+001557 at $z = 2.5528$, which was detected as an unresolved source in the Atacama Cosmology Telescope (ACT) equatorial survey. Our spatially resolved spectral line data support the derivation of a gravitational lens model from 37 independent velocity channel maps using a pixel-based algorithm, from which we infer a velocity-dependent magnification factor $\mu \approx 7-22$ with a luminosity-weighted mean \left\approx 13. The resulting source-plane reconstruction is consistent with a rotating disk, although other scenarios cannot be ruled out by our data. After correction for lensing, we derive a line luminosity $L^{\prime}_{\rm CO(3-2)}= (5.53\pm 0.69) \times 10^{10}\,{\rm \,K\,km\,s^{-1}\,pc^{2}}$, a cold gas mass $M_{{\rm gas}}= (3.86 \pm 0.33) \times 10^{10}\,M_{\odot}$, a dynamical mass $M_{\rm dyn}\,{\rm sin}^2\,i = 3.9^{+1.8}_{-1.5} \times 10^{10}\,M_{\odot}$, and a gas mass fraction $f_{\rm gas}\,{\rm csc}^2\,i = 1.0^{+0.8}_{-0.4}$. The line brightness temperature ratio of $r_{3,1}\approx 1.6$ relative to a Green Bank Telescope CO($J=1-0$) detection may be elevated by a combination of external heating of molecular clouds, differential lensing, and/or pointing errors.Comment: 8 pages, 5 figures, accepted to Ap

Cbfa-1 mediates nitric oxide regulation of MMP-13 in osteoblasts.

During bone development, osteoblast differentiation requires remodeling of the extracellular matrix. Although underlying mechanisms have not been elucidated, evidence points to the participation of the nitric oxide (NO) and cyclic guanosine 3',5'-monophosphate (cGMP) system. Here, we detected increased matrix metalloproteinase (MMP)-13 mRNA, protein and activity, as well as increased inducible NO synthase (iNOS) and NO production during the differentiation of MC3T3-E1 osteoblasts. Transcriptional activity of the MMP-13 promoter was augmented by NO, 8-bromo-cGMP (8-Br-cGMP), and by a dominant-positive form of protein kinase G (PKG1-alpha). The stimulatory effect on the MMP-13 promoter was partially inhibited by mutation of the osteoblast-specific element 2 (OSE-2) binding site. Core binding factor-1 (Cbfa-1) expression peaked at 7 days of differentiation, and was phosphorylated by PKG in vitro. Cbfa-1 was localized to cell nuclei, and its translocation was inhibited by the iNOS inhibitor 1400W. Immunohistological examination revealed that MMP-13 and Cbfa-1 expression levels are both reduced in 17-day-old embryos of iNOS-deficient mice. Silencing of Cbfa-1 mRNA blocked MMP-13 expression without interfering with endogenous NO production, confirming its role in NO-induced MMP-13 expression by MC3T3-E1 cells. The results described here suggest a mechanism by which NO regulates osteogenesis.S

IFE Plant Technology Overview and contribution to HiPER proposal

HiPER is the European Project for Laser Fusion that has been able to join 26 institutions and signed under formal government agreement by 6 countries inside the ESFRI Program of the European Union (EU). The project is already extended by EU for two years more (until 2013) after its first preparatory phase from 2008. A large work has been developed in different areas to arrive to a design of repetitive operation of Laser Fusion Reactor, and decisions are envisioned in the next phase of Technology Development or Risk Reduction for Engineering or Power Plant facilities (or both). Chamber design has been very much completed for Engineering phase and starting of preliminary options for Reactor Power Plant have been established and review here

Re-framing the climate change debate in the livestock sector: mitigation and adaptation options

Livestock play a key role in the climate change debate. As with crop-based agriculture, the sector is both a net greenhouse gas emitter and vulnerable to climate change. At the same time, it is an essential food source for millions of people worldwide, with other functions apart from food security such as savings and insurance. By comparison with crop-based agriculture, the interactions of livestock and climate change have been much less studied. The debate around livestock is confusing due to the coexistence of multiple livestock farming systems with differing functions for humans, greenhouse gas (GHG) emission profiles and different characteristics and boundary issues in their measurement, which are often pooled together. Consequently, the diversity of livestock farming systems and their functions to human systems are poorly represented and the role of the livestock sector in the climate change debate has not been adequately addressed. In this article, building upon the Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC 5AR) findings, we review recent literature on livestock and climate change so as better to include this diversity in the adaptation and mitigation debate around livestock systems. For comparative purposes we use the same categories of managerial, technical, behavioral and policy-related action to organize both mitigation and adaptation options. We conclude that different livestock systems provide different functions to different human systems and require different strategies, so they cannot readily be pooled together. We also observe that, for the different livestock systems, several win-win strategies exist that effectively tackle both mitigation and adaptation options as well as food security