1,161 research outputs found
Genomics for transforming yam breeding
Yam (Dioscorea spp.), a multispecies,
polyploidy, and vegetatively
propagated crop, is an economically
important staple food for more than
300 million people in West Africa,
Asia, Oceania, and the Caribbean.
The five major yam-producing
countries in West Africa (Bénin,
Côte d’Ivoire, Ghana, Nigeria,
and Togo) account for 93% of
worldwide production. Dioscorea
rotundata and D. alata are the
species most commonly cultivated
in West Africa1. The genetic
improvement of yam is faced
with several constraints, including
the long growth cycle (about 8
months or more), dioecy, plants
that flower poorly or not at all,
polyploidy, vegetative propagation,
heterozygous genetic background,
and poor knowledge about the
genetics of the crop2
Yam breeding at IITA: achievements, challenges, and prospects
African food system
Yam (Dioscorea spp.) is a multispecies,
clonally propagated crop
cultivated for its starchy tubers.
About 10 species are widely
cultivated around the world, but
only D. rotundata, D. alata, and
D. cayenensis are the most widely
cultivated species in West Africa,
accounting for 93% of the global
yam production. Since inception,
IITA R4D efforts have focused on
developing new varieties of yam
with desired agronomic and quality
traits and to improve yam-based
cropping systems
Stress analysis of finite anisotropic plates with cutouts under displacement boundary conditions
XI CONGRESO NACIONAL DE MATERIALES COMPUESTOS. Celebrado en Móstoles los días 6, 7 y 8 de julio de 2015The aim of this article is to provide an analytical tool to estímate the stress
concentration in anisotropic plates weakened by a circular or elliptical hole; it is
achieved by developing Lekhnitskii formalism in order to allow fínite boundary effects
to be added (original formulation considers infinite plates). Only membrane problem is
herein considered, particularly when prescribed displacements are applied at externa!
boundaries, which could simulate boundary conditions of a manhole structure between
wing spars. A boundary collocation method in conjunction with a least squares
approach is used to solve the problem.Ministerio de Economía y Competitividad de España DPT2012-3718
The pitfall-trap of species conservation priority setting
This an accepted author's manuscript (AAM) version of an article published in Biodiversity and Conservation, 20 (2011): 663-68
Metabolite profiling of yam (Dioscorea spp.) accessions for use in crop improvement programmes
Article purchased; Published online: 14 Oct. 2017Introduction Ninety-seven percent of yam (Dioscorea spp.) production takes place in low income food deficit countries (LIFDCs) and the crop provides 200 calories a day to approximately 300 million people. Therefore, yams are vital for food security. Yams have high-yield potential and high market value potential yet current breeding of yam is hindered by a lack of genomic information and genetic resources. New tools are needed to modernise breeding strategies and unlock the potential of yam to improve livelihood
in LIFDCs.
Objectives Metabolomic screening has been undertaken on a diverse panel of Dioscorea accessions to assess the utility of the approach for advancing breeding strategies in this understudied crop. Methods Polar and lipophilic extracts from tubers of accessions from the global yam breeding program have been
comprehensively profiled via gas chromatography-mass spectrometry.
Results A visual pathway representation of the measured yam tuber metabolome has been delivered as a resource for biochemical evaluation of yam germplasm. Over 200 compounds were routinely measured in tubers, providing a major advance for the chemo-typing of this crop. Core biochemical redundancy concealed trends that were only elucidated following detailed mining of global metabolomics data. Combined analysis on leaf and tuber material identified a subset of metabolites which allow accurate species classification and highlighted the potential of predicting tuber composition from leaf profiles. Metabolic variation was accessionspecific
and often localised to compound classes, which will aid trait-targeting for metabolite markers.
Conclusions Metabolomics provides a standalone platform with potential to deliver near-future crop gains for yam. The approach compliments the genetic advancements currently underway and integration with other ‘–omics’ studies will deliver a significant advancement to yam breeding strategies
Identifying past social-ecological thresholds to understand long-term temporal dynamics in Spain
A thorough understanding of long-term temporal social-ecological dynamics at the national scale helps to explain the current condition of a country’s ecosystems and to support environmental policies to tackle future sustainability challenges. We aimed to develop a methodological approach to understand past long-term (1960-2010) social-ecological dynamics in Spain. First, we developed a methodical framework that allowed us to explore complex social-ecological dynamics among biodiversity, ecosystem services, human well-being, drivers of change, and institutional responses. Second, we compiled 21 long-term, national-scale indicators and analyzed their temporal relationships through a redundancy analysis. Third, we used a Bayesian change point analysis to detect evidence of past social-ecological thresholds and historical time periods. Our results revealed that Spain has passed through four socialecological thresholds that define five different time periods of nature and society relationships. Finally, we discussed how the proposed methodological approach helps to reinterpret national-level ecosystem indicators through a new conceptual lens to develop a more systems-based way of understanding long-term social-ecological patterns and dynamicsThis work was supported by the Biodiversity Foundation (http://www.fundacion-biodiversidad.es/) of the Spanish Ministry of Agriculture, Food and Environment. Partial
financial support was also provided by the Ministry of Economy and Competitiveness of Spain (project CGL2014-53782-P: ECOGRADIENTES). The Spanish National Institute for
Agriculture and Food Research and Technology (INIA) funded Marina García-Llorente as part of the European Social Fund. Blanca González García-Mon participated in this article as a “la
Caixa” Banking Foundation scholar. The funders had no role in the study design, data collection and analysis, preparation of the report, or the decision to submit the study for publicatio
An Expert Systems for Homeopatic Glaucoma Treatment (SEHO)
In this article, an Expert System for Homeopathic Glaucoma Treatment (SEHO) is presented, the task of which is to assist ophthalmologists in selecting the most appropriate therapy for a patient diagnosed as having glaucoma. It is based on techniques proper to homeopathic medicine, a trend that is gaining more and more supporters all over the world, but in which real experts are few and far between. After a brief overview of the state of the art, the authors describe in detail on the development of the system, for which the IDEAL methodology, designed for knowledge-based system development, was used
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