Synchronization of interconnected networks: the role of connector nodes

In this Letter we identify the general rules that determine the synchronization properties of interconnected networks. We study analytically, numerically and experimentally how the degree of the nodes through which two networks are connected influences the ability of the whole system to synchronize. We show that connecting the high-degree (low-degree) nodes of each network turns out to be the most (least) effective strategy to achieve synchronization. We find the functional relation between synchronizability and size for a given network-of-networks, and report the existence of the optimal connector link weights for the different interconnection strategies. Finally, we perform an electronic experiment with two coupled star networks and conclude that the analytical results are indeed valid in the presence of noise and parameter mismatches.Comment: Accepted for publication in Physical Review Letters. Main text: 5 pages, 4 figures. Supplemental material: 8 pages, 3 figure

Virtual pollination trade uncovers global dependence on biodiversity of developing countries

Nations’ food consumption patterns are increasingly globalized and trade dependent. Natural resources used for agriculture (e.g., water, pollinators) are hence being virtually exchanged across countries. Inspired by the virtual water concept, we, herein, propose the concept of virtual biotic pollination flow as an indicator of countries’ mutual dependence on biodiversity-based ecosystem services and provide an online tool to visualize trade flow. Using information on 55 pollinator-dependent crop markets (2001–2015), we show that countries with higher development level demand high levels of biodiversity-based services to sustain their consumption patterns. Such patterns are supported by importation of virtual biotic pollination (up to 40% of national imports of pollinator-dependent crops) from developing countries, stimulating cropland expansion. Quantifying virtual pollination flow can help develop new global socioeconomic policies to meet the interconnected challenges of biodiversity loss, ecosystem health, and social justice.info:eu-repo/semantics/publishedVersio

Evaluación en laboratorios e invernadero de extractos vegetales de barbasco (Pyllantus sp) Marigol (Tagetes patula) y semilla de Neem (Azadirachta A. Juss) para el control de Meloidogyne javanica y Fusarium oxysporum en tomate de mesa (Lycopersicon sculetum)

sumarios (En, Es)El cultivó de tomate (lycoperslcon scu/enlum) es una de las hortalizas de mayor área sembrada o nivel mundial, China ocupa el primer lugar en producción con 25.5 millones de toneladas seguido de USA con 2.3 millones de toneladas. Para el año de 1997 lo producción mundial de tomate de mesa fue de 88.7 millones de toneladas. En Colombia para el mismo año, el áreo sembrado fue de I 2,800 hectáreas para uno producción de 37 4 261 toneladas con lo cual participó en el mercado mundial con un 0.3% en exportaciones; el incremento en la producción desde 1998 al 2002 no creció más del 5% (FAOl998-2002) El tomate se cultivó en todo el país, o lo intemperie y bajo invernadero cerca del 80% de la producción está concentrada en los departamentos de Cundinamarca, Norte de Santander, Valle, Caldas. Huila, Tolima, Risaralda y Antioquia. Tradicionalmente se cultivan las variedades chonto y milano, pero en Atlántico, Guajira y Santander, se cultivan las variedades Rio Grande y Tomate Ciruelo.Tomate-Solanum lycopersicu

Protein content and quality of seeds in central mexican maize (Zea mays) accessions

Mexico is the center of the origin, domestication and diversity of maize. This cereal is the main constituent of the Mexican diet, especially in low-income families. In this research, 10 maize accessions derived from a large landrace collection, with the 'INIFAP-QPM' accession and a 'regional landrace' as controls, were studied to identify the accessions with the best biochemical and physiological characteristics showing good adaptation to 'El Bajío' (regional center in Mexico) conditions. The accessions were statistically superior to the two controls in the germination and accelerated aging tests. In the assessment of variable plumule length, variability was observed among the accessions, but the controls showed the lowest values. Protein contents in different fractions (albumins, globulins, prolamins and glutelins) showed variability as did oil and fiber contents. The 'HRH2015' accession showed high contents of albumins and globulins and low contents of prolamins and glutelins. The 'regional landrace' accession exhibited the highest contents of glutelins and prolamins but the lowests content of globulins and albumins. The total percentage of proteins showed variability among the accessions, but the values were within those reported in the literature. The 'RQ2015' accession presented the highest oil content (5.25%). The electrophoretic patterns of prolamins were obtained, and some differences were observed between them. The 'regional landrace' presented the lowest protein content, which was significantly different from those of the other accessions evaluated. This research demonstrates biochemical, germination and vigor variability among the studied maize accessions. Highlights The protein fraction content showed highly significant differences between the accessions, the accession 'HRH2015' presented the highest total soluble protein content. The 'HRH2015' accession contained high percentages of the albumin, globulin and prolamin fractions, but a lower percentage of the glutelin fraction, which is a suitable material for breeding. The accessions 'A2015', 'POL2015' and 'FVR12015' were superior in seed quality, these accessions could be used in a future breeding program.Mexico is the center of the origin, domestication and diversity of maize. This cereal is the main constituent of the Mexican diet, especially in low-income families. In this research, 10 maize accessions derived from a large landrace collection, with the 'INIFAP-QPM' accession and a 'regional landrace' as controls, were studied to identify the accessions with the best biochemical and physiological characteristics showing good adaptation to 'El Bajío' (regional center in Mexico) conditions. The accessions were statistically superior to the two controls in the germination and accelerated aging tests. In the assessment of variable plumule length, variability was observed among the accessions, but the controls showed the lowest values. Protein contents in different fractions (albumins, globulins, prolamins and glutelins) showed variability as did oil and fiber contents. The 'HRH2015' accession showed high contents of albumins and globulins and low contents of prolamins and glutelins. The 'regional landrace' accession exhibited the highest contents of glutelins and prolamins but the lowests content of globulins and albumins. The total percentage of proteins showed variability among the accessions, but the values were within those reported in the literature. The 'RQ2015' accession presented the highest oil content (5.25%). The electrophoretic patterns of prolamins were obtained, and some differences were observed between them. The 'regional landrace' presented the lowest protein content, which was significantly different from those of the other accessions evaluated. This research demonstrates biochemical, germination and vigor variability among the studied maize accessions. Highlights The protein fraction content showed highly significant differences between the accessions, the accession 'HRH2015' presented the highest total soluble protein content. The 'HRH2015' accession contained high percentages of the albumin, globulin and prolamin fractions, but a lower percentage of the glutelin fraction, which is a suitable material for breeding. The accessions 'A2015', 'POL2015' and 'FVR12015' were superior in seed quality, these accessions could be used in a future breeding program

Species distribution models for crop pollination: a modelling framework applied to Great Britain

Insect pollination benefits over three quarters of the world\u27s major crops. There is growing concern that observed declines in pollinators may impact on production and revenues from animal pollinated crops. Knowing the distribution of pollinators is therefore crucial for estimating their availability to pollinate crops; however, in general, we have an incomplete knowledge of where these pollinators occur. We propose a method to predict geographical patterns of pollination service to crops, novel in two elements: the use of pollinator records rather than expert knowledge to predict pollinator occurrence, and the inclusion of the managed pollinator supply. We integrated a maximum entropy species distribution model (SDM) with an existing pollination service model (PSM) to derive the availability of pollinators for crop pollination. We used nation-wide records of wild and managed pollinators (honey bees) as well as agricultural data from Great Britain. We first calibrated the SDM on a representative sample of bee and hoverfly crop pollinator species, evaluating the effects of different settings on model performance and on its capacity to identify the most important predictors. The importance of the different predictors was better resolved by SDM derived from simpler functions, with consistent results for bees and hoverflies. We then used the species distributions from the calibrated model to predict pollination service of wild and managed pollinators, using field beans as a test case. The PSM allowed us to spatially characterize the contribution of wild and managed pollinators and also identify areas potentially vulnerable to low pollination service provision, which can help direct local scale interventions. This approach can be extended to investigate geographical mismatches between crop pollination demand and the availability of pollinators, resulting from environmental change or policy scenarios