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

T-Duality and Homological Mirror Symmetry of Toric Varieties

Let $X_\Sigma$ be a complete toric variety. The coherent-constructible correspondence $\kappa$ of \cite{FLTZ} equates \Perf_T(X_\Sigma) with a subcategory Sh_{cc}(M_\bR;\LS) of constructible sheaves on a vector space M_\bR. The microlocalization equivalence $\mu$ of \cite{NZ,N} relates these sheaves to a subcategory Fuk(T^*M_\bR;\LS) of the Fukaya category of the cotangent T^*M_\bR. When X_\Si is nonsingular, taking the derived category yields an equivariant version of homological mirror symmetry, DCoh_T(X_\Si)\cong DFuk(T^*M_\bR;\LS), which is an equivalence of triangulated tensor categories. The nonequivariant coherent-constructible correspondence $\bar{\kappa}$ of \cite{T} embeds \Perf(X_\Si) into a subcategory Sh_c(T_\bR^\vee;\bar{\Lambda}_\Si) of constructible sheaves on a compact torus T_\bR^\vee. When X_\Si is nonsingular, the composition of $\bar{\kappa}$ and microlocalization yields a version of homological mirror symmetry, DCoh(X_\Sigma)\hookrightarrow DFuk(T^*T_\bR;\bar{\Lambda}_\Si), which is a full embedding of triangulated tensor categories. When X_\Si is nonsingular and projective, the composition $\tau=\mu\circ \kappa$ is compatible with T-duality, in the following sense. An equivariant ample line bundle \cL has a hermitian metric invariant under the real torus, whose connection defines a family of flat line bundles over the real torus orbits. This data produces a T-dual Lagrangian brane $\mathbb L$ on the universal cover T^*M_\bR of the dual real torus fibration. We prove \mathbb L\cong \tau(\cL) in Fuk(T^*M_\bR;\LS). Thus, equivariant homological mirror symmetry is determined by T-duality.Comment: 34 pages, 2 figures. The previous version of this paper has now been broken into two parts. The other part is available at arXiv:1007.005

Director-Matcher Task Project

The Director-Matcher Task Project aims to create a new flexible web toolkit for the collection of data for psychology, linguistic, and cognitive science based research. The toolkit was initially developed to record instances of code switching, a linguistic concept concerned with a speaker alternating between multiple languages during one conversation. The project is based on Toy Task experiments, a modification of the director-matcher task, developed at the University of Bangor’s bilingual research center. Traditionally, two subjects separated by a wall were tasked with matching object placement on a set of chessboards through vocal communication. The Director-Matcher Task Project uses web technologies such as HTML5, JavaScript, and PHP to digitize the concept. The toolkit separates the board and participants physically by providing an online interface for conducting code switching studies, allowing research to be carried out by subjects all over the world without direct physical contact. It also attempts to limit the cognitive bias of participants as much as possible, by removing as many references to a specific language as possible from the toy-task itself, to help foster more pure and natural code switching data. The toolkit further fosters the ability to analyze session voice data and board states to create corpora for the code switching experiments.http://opus.ipfw.edu/stu_symp2014/1020/thumbnail.jp

Marine power distribution system fault location using a portable injection unit

A portable injection unit for Active Impedance Estimation (AIE) is built and tested in a DC zonal marine power distribution system to provide useful information for system protection and restoration. The portable unit generates current “spikes” and injects them into the system once short circuit faults are detected (by measuring the system voltage drop). The faulted system impedance can be estimated by AIE and comparing the estimated impedance with the pre-calibrated value, the fault location can be determined. The proposed method does not rely on system fault transient information or communication from the remote-end measurement and offers fast and accurate fault location in DC marine distribution systems. The proposed method has been tested and validated on a 750V, 2 MW twin bus DC Commercial Test Facility with the system both de-energised and energised

Human-machine scientific discovery

International audienceHumanity is facing existential, societal challenges related to food security, ecosystem conservation, antimicrobial resistance, etc, and Artificial Intelligence (AI) is already playing an important role in tackling these new challenges. Most current AI approaches are limited when it comes to ‘knowledge transfer’ with humans, i.e. it is difficult to incorporate existing human knowledge and also the output knowledge is not human comprehensible. In this chapter we demonstrate how a combination of comprehensible machine learning, text-mining and domain knowledge could enhance human-machine collaboration for the purpose of automated scientific discovery where humans and computers jointly develop and evaluate scientific theories. As a case study, we describe a combination of logic-based machine learning (which included human-encoded ecological background knowledge) and text-mining from scientific publications (to verify machine-learned hypotheses) for the purpose of automated discovery of ecological interaction networks (food-webs) to detect change in agricultural ecosystems using the Farm Scale Evaluations (FSEs) of genetically modified herbicide-tolerant (GMHT) crops dataset. The results included novel food-web hypotheses, some confirmed by subsequent experimental studies (e.g. DNA analysis) and published in scientific journals. These machine-leaned food-webs were also used as the basis of a recent study revealing resilience of agro-ecosystems to changes in farming management using GMHT crops

Optical and Electronic Properties of Femtosecond Laser-Induced Sulfur-Hyperdoped Silicon N+/P Photodiodes

Impurity-mediated near-infrared (NIR) photoresponse in silicon is of great interest for photovoltaics and photodetectors. In this paper, we have fabricated a series of n+/p photodetectors with hyperdoped silicon prepared by ion-implantation and femtosecond pulsed laser. These devices showed a remarkable enhancement on absorption and photoresponse at NIR wavelengths. The device fabricated with implantation dose of 1014 ions/cm2 has exhibited the best performance. The proposed method offers an approach to fabricate low-cost broadband silicon-based photodetectors

A categorification of Morelli's theorem

We prove a theorem relating torus-equivariant coherent sheaves on toric varieties to polyhedrally-constructible sheaves on a vector space. At the level of K-theory, the theorem recovers Morelli's description of the K-theory of a smooth projective toric variety. Specifically, let $X$ be a proper toric variety of dimension $n$ and let M_\bR = \mathrm{Lie}(T_\bR^\vee)\cong \bR^n be the Lie algebra of the compact dual (real) torus T_\bR^\vee\cong U(1)^n. Then there is a corresponding conical Lagrangian \Lambda \subset T^*M_\bR and an equivalence of triangulated dg categories \Perf_T(X) \cong \Sh_{cc}(M_\bR;\Lambda), where \Perf_T(X) is the triangulated dg category of perfect complexes of torus-equivariant coherent sheaves on $X$ and \Sh_{cc}(M_\bR;\Lambda) is the triangulated dg category of complex of sheaves on M_\bR with compactly supported, constructible cohomology whose singular support lies in $\Lambda$. This equivalence is monoidal---it intertwines the tensor product of coherent sheaves on $X$ with the convolution product of constructible sheaves on M_\bR.Comment: 20 pages. This is a strengthened version of the first half of arXiv:0811.1228v3, with new results; the second half becomes arXiv:0811.1228v