Reconciling Techno-simplicity and Eco-complexity for future food security

Ecological intensification has been proposed as a paradigm for ensuring global food security while preserving biodiversity and ecosystem integrity. Ecologicalintensification was originally coined to promote precise site-specific farming practices aimed at reducing yield gaps, while avoiding negative environmental impacts (techno-simplicity). Recently, it has been extended to stress the importance of landscape complexity to preserve biodiversity and ecosystem services (eco-complexity). While these perspectives on ecological intensification may seem distinct, they are not incompatible and should be interwoven to create more comprehensive and practical solutions. Here, we argue that designing cropping systems to be more diverse, across space and time would be an effective route to accomplish environmentally-friendly intensification of crop production. Such a novel approach will require better integration of knowledge at the landscape level for increasing agro-biodiversity(focused on interventions outside fields) with strategies diversifying croppingsystems to manage weeds and pests (focused on interventions inside fields).Fil: Poggio, Santiago Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Producción Vegetal; ArgentinaFil: Macfadyen, Sarina. CSIRO; AustraliaFil: Bohan, David A.. Institut National de la Recherche Agronomique; Franci

Brans-Dicke wormholes in nonvacuum spacetime

Analytical wormhole solutions in Brans-Dicke theory in the presence of matter are presented. It is shown that the wormhole throat must not be necessarily threaded with exotic matter.Comment: Minor corrections, to be published in Phys. Rev.

Quantum localized states in photonic flat-band lattices

The localization of light in flat-band lattices has been recently proposed and experimentally demonstrated in several configurations, assuming a classical description of light. Here, we study the problem of light localization in the quantum regime. We focus on quasi one-dimensional and two-dimensional lattices which exhibit a perfect flat-band inside their linear spectrum. Localized quantum states are constructed as eigenstates of the interaction Hamiltonian with a vanishing eigenvalue and a well defined total photon number. These are superpositions of Fock states with probability amplitudes given by positive as well as negative square roots of multinomial coefficients. The classical picture can be recovered by considering poissonian superpositions of localized quantum states with different total photon number. We also study the separability properties of flat band quantum states and apply them to the transmission of information via multi-core fibers, where these states allow for the total passive suppression of photon crosstalk and exhibit robustness against photon losses. At the end, we propose a novel on-chip setup for the experimental preparation of localized quantum states of light for any number of photons.Comment: 12 pages, 5 figure

Cylindrically symmetric spinning Brans-Dicke spacetimes with closed timelike curves

We present here three new solutions of Brans-Dicke theory for a stationary geometry with cylindrical symmetry in the presence of matter in rigid rotation with $T^\mu_\mu\neq 0$. All the solutions have eternal closed timelike curves in some region of the spacetime, the size of which depends on $\omega$. Moreover, two of them do not go over a solution of general relativity in the limit $\omega \to \infty$.Comment: revtex, 10 pages, 1 figure in p

Detection and Mapping of Decoupled Stellar and Ionized Gas Structures in the Ultraluminous Infrared Galaxy IRAS 12112+0305

Integral field optical spectroscopy with the INTEGRAL fiber-fed system and HST optical imaging are used to map the complex stellar and warm ionized gas structure in the ultraluminous infrared galaxy IRAS 12112+0305. Images reconstructed from wavelength-delimited extractions of the integral field spectra reveal that the observed ionized gas distribution is decoupled from the stellar main body of the galaxy, with the dominant continuum and emission-line regions separated by projected distances of up to 7.5 kpc. The two optical nuclei are detected as apparently faint emission-line regions, and their optical properties are consistent with being dust-enshrouded weak-[OI] LINERs. The brightest emission-line region is associated with a faint (m_{I}= 20.4), giant HII region of 600 pc diameter, where a young (about 5 Myr) massive cluster of about 2 $\times$ 10$^7$ $M_{\odot}$ dominates the ionization. Internal reddening towards the line-emitting regions and the optical nuclei ranges from 1 to 8 magnitudes, in the visual. Taken the reddening into aacount, the overall star formation in IRAS 12112+0305 is dominated by starbursts associated with the two nuclei and corresponding to a star formation rate of 80 $M_{\odot}$ yr$^{-1}$.Comment: 2 figures, accepted to Ap.J. Letter

Study of GaAs(Ti) thin films as candidates for IB solar cells manufacturing

Thin films of GaAs(Ti) have been deposited by sputtering on glass and n_GaAs substrates under different process conditions. Optical characteristics of these samples have been analyzed to study the potential of this material in intermediate Band solar cell manufacturing.Postprint (published version