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Community Ecology
Authors: A. García-Villaraco Velasco, A. Probanza, F. Gutierrez Mañero, B. Ramos, and J. Lucas García

Activity and functional diversity of rhizosphere bacterial communities and fungal composition were studied in order to assess the effects of different genotypes (N8035, N224 and N8637) of Arabidopsis thaliana on these communities growing in different soils. Genotype effect and soil effect were studied independently. Also, the interactions between both factors (genotypes and soils) were considered. The activity was determined by thymidine and leucine incorporation analysis, and Biolog ECO plates were used to study bacterial functional diversity. Additionally, fungi groups (genera and/or species) were studied in the different rhizospheres. Statistical differences on thymidine incorporation between plant genotypes were only found in two of the soils. In addition, functional diversity (measured by Shanonn-Weaver index), showed statistical differences only in soil 1 for line N8035 (line B) vs . the other lines. Redundancy analysis (RDA) performed with Biolog data indicated and important effect of soil type, but also an effect of genotype since line N8035 (line B) was separated from the other lines within each soil in the RDA ordination, in spite of genotypic differences between them were minimum. Furthermore, carboxylic acids and amino acids were found to be the Biolog plate substrates with more influence in samples ordination in the Redundancy Analysis (RDA). However, fungi seem to be less labile to plant selection than bacteria probably due to a lower turn-over time of fungi than bacteria coupled with the short phenology of Arabidopsis . In this paper, plant-soil-micro-organism relationships in the rhizosphere were studied, and the complex interactions between them were highlighted. More studies are necessary to go deep in these interactions and to be able to asses the impact of genetically modified plants.

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The anthocyanin pattern of 18 grape cultivars grown under the same conditions during several years, and also the anthocyanin pattern of wines made from them, using the same winemaking technology, has been studied by HPLC. Chromatographic data indicate that every grape cultivar present a characteristic anthocyanin pattern, that is reflected in wines made from them. Two-way ANOVA and variance component analysis point out that the anthocyanin pattern of grapes and wines is mostly affected by the genetic characteristics of grape cultivars. Moreover, the use of multivariate statistical analysis (principal component analysis and discriminant analysis) allows the classification of grapes and wines into several groups on the basis of their anthocyanin pattern, and shows that the anthocyanin pattern of young single-cultivar wines is related to the anthocyanin pattern of grapes used for winemaking. Results may be relevant for using the anthocyanin pattern of young single-cultivar wines as an analytical tool to determine the grape cultivar used to make them.

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Soil structure stability depends on several factors and its assessment is conducted using different methods and prediction indices. One of the indicators is soil organic matter (SOM), since this helps to keep mineral particles together against destabilizing forces such as wetting and raindrop impact. However, previous studies have emphasized the relationship between aggregate stability and SOM content without considering its type or quality. Therefore, in this study the association between the quality and content of SOM and the structural stability of the surface layer was evaluated in three soils used for growing malting barley in the southern part of Hidalgo State, Mexico. With simple random sampling nine observation points were selected in each soil, where samples were taken in order to determine the stable aggregate size distribution, particle size distribution, content and fractionation of SOM, and the prediction indices of surface sealing and crusting derived from these characteristics. The soils showed low structural stability (except in Apan), as shown by the percentage runoff recorded in the field. There was a close association between the size (from 4 to 2 mm and <0.25 mm) of water-stable aggregates and the different fractions of SOM, while the fulvic acid (FA) fraction had a negative relationship with smaller aggregates (R = −0.84). Finally, it was found that only the FAO crusting index was able to predict the structural stability level in the soil.

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Community Ecology
Authors: A.F.S. Garcia, A.M. Garcia, S.R. Vollrath, F. Schneck, C.F.M. Silva, Í.J. Marchetti, and J.P. Vieira

Food partitioning among coexisting species in different habitats remains an important research topic in trophic ecology. In this work, we combined carbon and nitrogen stable isotope ratios and stomach content analyses to investigate differences in diet and niche overlap of two congeneric juvenile mullet species (Mugil curema and Mugil liza) coexisting in a marine surf-zone and an estuarine zone in southern Brazil (29oS). These habitats have contrasting levels of food availability, especially in terms of prey diversity, with higher microalgae diversity in the estuary than in the marine surf-zone. In these contrasting conditions, we predicted that both mullet species will have (a) higher niche overlap and smaller niche breadth at the marine surf-zone due to the common exploration of highly abundant surf-zone diatoms and (b) lower niche overlap and higher niche breadth inside the estuary due to selective feeding on more diverse food resources. Isotope niche areas (measured as standard ellipse areas) were higher in the estuary (6.10 and 6.18) than in the marine surf-zone (3.68 and 3.37) for both M. curema and M. liza, respectively. We observed an overlap of 52% in isotopic niches of both species in the marine surf-zone and none in the estuary. We also found contrasting patterns in the diet composition between species according to the habitat. At the marine surfzone, diatoms of the classes Bacillariophyceae and Coscinodiscophyceae dominated (> 99%) the food content of both mullet species. In contrast, green algae, cyanobacteria, dinoflagellates and flagellates comprised the diet of both species in the estuary. These results could be explained by spatial differences in food availability (especially regarding diversity of microalgae) between both habitats. At the marine site, both species explored the most abundant microalgae available (mostly the surf-zone diatom Asterionellopsis cf. guyunusae and fragments of Coscinodiscus), whereas in the estuary both species shifted their diets to explore the greater diversity of microalgae resources. Overall, our findings revealed that niche partitioning theory could not fully predict changes in breadth and overlap of food niches of estuarine dependent fish species with complex life cycles encompassing marine to estuarine systems with contrasting food availabilities.

Open access

The best alternative for reducing citrus production costs is mechanization. Machine vision is a reliable technology for the automatic inspection of fresh fruits and vegetables that can be adapted to harvesting machines. In these, fruits can be inspected before sending them to the packinghouse and machine vision provides important information for subsequent processing and avoids spending further resources in non-marketable fruit. The present work describes a computer vision system installed on a harvesting machine developed jointly by IVIA and a Spanish enterprise. In this machine, hand pickers directly drop the fruit as they collect it, which results in an important increase of productivity. The machine vision system is placed over rollers in order to inspect the produce, and separate those that can be directly sent to the fresh market from those that do not meet minimal quality requirements but can be used by the processing industry, based on color, size and the presence of surface damages. The system was tested under field conditions.

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The aim of this research was to assess the total antioxidant activity (TAA) of lipophilic (Lextr) and hydrophilic (Hextr) tomato extracts using in vitro chemical tests and cell-based assays, focusing on possible synergistic actions between tomato antioxidants. Both Hextr and Lextr were HPLC analysed for their carotenoids, phenolic compounds, and ascorbic acid contents. For the evaluation of TAA, extracts were assayed alone or in combination using in vitro chemical tests (TEAC, FRAP) and cell-based (CAA) assays using human hepatoma (HepG2) and human histiocytic lymphoma (U937) cells. The only carotenoid detected in Lextr was lycopene, while a mixture of phenolic compounds (chlorogenic acid, caffeic acid, and rutin) was identified in Hextr. Ascorbic acid was not found either in Hextr or in Lextr. Upon extract combination (1:1, v/v), the FRAP assay revealed additive action between Lextr and Hextr, whilst a slight synergistic action was observed in TAA as measured by the TEAC assay. Synergistic action was better revealed when TAA was analysed using either U937 or HepG2 cells. This could be explained by the presence of a multiphase media (cell membrane and extra- and intracellular media) that might facilitate the distribution and interaction of antioxidants with different polarities and different mechanisms of action.

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Community Ecology
Authors: F.A. Rodríguez-Zaragoza, M. Ortiz, F. Berrios, L. Campos, A. de Jesús-Navarrete, J. Castro-Pérez, A. Hernández-Flores, M. García-Rivas, F. Fonseca-Peralta, and E. Gallegos-Aguilar

Banco Chinchorro is the largest reef in the Mexican Caribbean. Historically, spiny lobster, queen conch and over 20 other reef species have been exploited here. Multispecies intervention management from an ecosystem perspective has been developed in this area; however, an assessment of the effects of such practices on ecosystem health is required. Five quantitative trophic models were constructed using Ecopath with Ecosim. The results show that, in terms of biomass, benthic autotrophs are the dominant group in all communities. Ecosystem Network Analysis indices showed that Cueva de Tiburones was the most mature, developed, complex and healthy subsystem, but, El Colorado and La Baliza were the subsystems most resistant to disturbances. The fisheries mainly concentrate on primary (La Baliza and Cueva de Tiburones sites) and secondary consumers (La Caldera, Chancay, and El Colorado). The greatest propagation of direct and indirect effects, estimated by Mixed Trophic Impacts and Ecosim simulations, were generated by the benthic autotrophs, small benthic epifauna, benthic-pelagic carnivorous fish and benthic carnivorous fish, among others. In contrast, the System Recovery Time showed different patterns among subsystems, indicating several compartments that reduce resilience. Considering the structure, dynamics, trophic functioning and ecosystem health of Banco Chinchorro, its ecological heterogeneity highlights the need for the design of a specific (by subsystem) management strategy, particularly because different species or functional groups present greater sensitivity to human interventions in each community.

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Acta Alimentaria
Authors: C. Cano-Molina, A. López-Fernández, N. Díaz-González, R. González-Barrio, N. Baenas, M.J. Periago, and F.J. García-Alonso

Abstract

Tomato is rich in different bioactive compounds, especially the carotenoid lycopene, which intake is associated with various health benefits. Post-harvest use of ultraviolet light (UV) and light-emitting diode (LED) has been shown to increase the concentration of tomato bioactive compounds. The aim of this study was to evaluate the effect of ultraviolet (A and C) and red-blue LED light on the concentration of carotenoids during a 7-days storage trial of mature green tomatoes. Exposure to combined UV and LED light nearly doubled the total carotenoid concentration and had no negative impact on sensory attributes.

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European Journal of Microbiology and Immunology
Authors: C. Alvarado-Esquivel, S. J. Pacheco-Vega, M. Salcedo-Jaquez, L. F. Sánchez-Anguiano, J. Hernández-Tinoco, E. Rábago-Sánchez, M. M. Centeno-Tinoco, I. D. Flores-Garcia, A. Ramos-Nevarez, S. M. Cerrillo-Soto, C. A. Guido-Arreola, I. Beristain-García, O. Liesenfeld, L. O. Berumen-Segovia, L. Saenz-Soto, and A. Sifuentes-Álvarez

Through a cross-sectional study design, 150 women attending public health centers with a history of stillbirths were examined for anti-Toxoplasma gondii IgG and IgM antibodies in Durango City, Mexico. Bivariate and multivariate analyses were used to assess the association of T. gondii seropositivity with the characteristics of the women with stillbirth history.

Of the 150 women (mean age: 32.09 ± 9.16 years) studied, 14 (9.3%) had anti-T. gondii IgG antibodies and six (42.9%) of them were also positive for anti-T. gondii IgM antibodies. Multivariate analysis showed that T. gondii seropositivity was associated with high frequency (4–7 days a week) of eating meat (OR = 5.52; 95% CI: 1.48–20.59; P = 0.01), history of lymphadenopathy (OR = 4.52; 95% CI: 1.14–17.82; P = 0.03), and history of surgery (OR = 8.68; 95% CI: 1.04–72.15; P = 0.04).

This is the first study on the seroepidemiology of T. gondii infection in women with a history of stillbirths in Mexico. The association of T. gondii exposure with a history of surgery warrants for further research. Risk factors for T. gondii infection found in the present survey may help to design optimal educational programs to avoid T. gondii infection.

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European Journal of Microbiology and Immunology
Authors: Dr. Cosme Alvarado-Esquivel, S. J. Pacheco-Vega, J. Hernández-Tinoco, M. M. Centeno-Tinoco, I. Beristain-García, L. F. Sánchez-Anguiano, O. Liesenfeld, E. Rábago-Sánchez, and L. O. Berumen-Segovia

Abstract

Through a cross-sectional study design, 326 women with a history of miscarriage were examined for anti-Toxoplasma gondii IgG and IgM antibodies in Durango City, Mexico. Prevalence association with sociodemographic, clinical, and behavioral characteristics in women with miscarriage was also investigated.

Twenty-two (6.7%) of the 326 women studied had anti-T. gondii IgG antibodies and two (0.6%) were also positive for anti-T. gondii IgM antibodies. Seroprevalence of T. gondii infection was not influenced by age, birth place, occupation, educational level, or socioeconomic status. In contrast, logistic regression showed that T. gondii exposure was associated with consumption of raw or undercooked meat (OR = 6.84; 95% CI: 1.04–44.95; P = 0.04) and consumption of chicken brains (OR = 18.48; 95% CI: 1.26–269.43; P = 0.03).

This is the first study on the seroepidemiology of T. gondii infection in women with a history of miscarriage in Northern Mexico. Of interest, we also observed an association of T. gondii exposure with consumption of chicken brains. Contributing factors for T. gondii exposure found in the present study should be taken into consideration for public health measures to avoid infection with T. gondii and its sequelae.

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