135 research outputs found

    High-resolution QTL mapping in Tetranychus urticae reveals acaricide-specific responses and common target-site resistance after selection by different METI-I acaricides

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    Arthropod herbivores cause dramatic crop losses, and frequent pesticide use has led to widespread resistance in numerous species. One such species, the two-spotted spider mite, Tetranychus urticae, is an extreme generalist herbivore and a major worldwide crop pest with a history of rapidly developing resistance to acaricides. Mitochondrial Electron Transport Inhibitors of complex I (METI-Is) have been used extensively in the last 25 years to control T. urticae around the globe, and widespread resistance to each has been documented. METI-I resistance mechanisms in T. urticae are likely complex, as increased metabolism by cytochrome P450 monooxygenases as well as a target-site mutation have been linked with resistance. To identify loci underlying resistance to the METI-I acaricides fenpyroximate, pyridaben and tebufenpyrad without prior hypotheses, we crossed a highly METI-I-resistant strain of T. urticae to a susceptible one, propagated many replicated populations over multiple generations with and without selection by each compound, and performed bulked segregant analysis genetic mapping. Our results showed that while the known H92R target-site mutation was associated with resistance to each compound, a genomic region that included cytochrome P450-reductase (CPR) was associated with resistance to pyridaben and tebufenpyrad. Within CPR, a single nonsynonymous variant distinguished the resistant strain from the sensitive one. Furthermore, a genomic region linked with tebufenpyrad resistance harbored a non-canonical member of the nuclear hormone receptor 96 (NHR96) gene family. This NHR96 gene does not encode a DNA-binding domain (DBD), an uncommon feature in arthropods, and belongs to an expanded family of 47 NHR96 proteins lacking DBDs in T. urticae. Our findings suggest that although cross-resistance to METI-Is involves known detoxification pathways, structural differences in METI-I acaricides have also resulted in resistance mechanisms that are compound-specific

    A methodology to downscale water demand data with application to the Andean region (Ecuador, Peru, Bolivia, Chile)

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    Mountainous regions are a hotspot for water scarcity and anthropogenic pressure on water resources. Substantial uncertainty surrounds projections of future climate and water availability. Furthermore, quantitative and distributed data on water demand are generally scarce, dispersed, and highly heterogeneous. This forms a major bottleneck to studying water resources issues and developing strategies to improve water resource management. Here we present a methodology to produce and evaluate high-resolution gridded maps of anthropogenic surface water demand with application to the Andean region. These data are disaggregated according to the major types of water demand: domestic users, irrigated area, and hydropower. This dataset was built by homogenizing, integrating, and interpolating data obtained from various national institutions in charge of water resource management as well as relevant global datasets. The maps can be used to research anthropogenic impacts on water resources, and to guide regional decision-making in regions such as the Andes

    Interlaboratory exercise for the analysis of carotenoids and related compounds in dried mango fruit (Mangifera indica L.)

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    An interlaboratory comparison was done for the analysis of carotenoids in freeze-dried mango. The study was performed from July to September 2018. Mango fruit was freeze-dried, homogenized, and packaged under vacuum conditions in portions of 6 g (test sample). Two test samples were sent to the participating laboratories for analysis. Laboratory results were rated using Z-scores in accordance with ISO 13528 and ISO 17043. The standard deviation for proficiency assessment (also called target standard deviation) was determined using a modified Horwitz function and varied between 10% and 25%, depending on the analyte. Out of 14 laboratories from 10 different countries, 9 laboratories (64%) obtained a satisfactory performance (Z ≤ 2) for the analysis of β-carotene. While for 7 laboratories that analyzed α-carotene, (9Z)-β-carotene, β-cryptoxanthin, and zeaxanthin, 4 laboratories (57%) obtained a satisfactory performance. However, only 2 laboratories out of 7 (29%) obtained a satisfactory performance for lutein. Based on the comparability of the analytical results, this study concludes that freeze-dried mango pulp can be used as a reference material for the analysis of α and β-carotene, (9Z)-β-carotene, β-cryptoxanthin, and zeaxanthin by applying different analytical procedures for their extraction and quantification

    TRY plant trait database - enhanced coverage and open access

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    Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    Frecuencia de comidas fuera de casa y calidad de hidratos de carbono y de grasas en el proyecto SUN

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    Objetivo: Investigar la asociación entre la frecuencia de comidas fuera de casa (CFC) con a) la calidad de hidratos de carbono y b) la calidad de grasas. Materiales y métodos: Se evaluaron 19.371 participantes de la cohorte SUN que completaron un cuestionario basal de frecuencia de consumo de alimentos previamente validado. Se utilizaron los índices de calidad de hidratos de carbono (ICHC) en una escala de 4 a 20 y de grasas (ICG) en una escala de 0,62 a 5,92. En ambos casos, a mayor puntuación mayor calidad. Se utilizó la regresión lineal múltiple para determinar la asociación entre la frecuencia de CFC (4 categorías) y la puntuación de ambos índices, y la regresión logística para medir la asociación entre la frecuencia de CFC y un bajo ICHC o ICG (<percentil 25). Resultados: Los participantes mostraron una media de ICHC e ICG de 11,3 (DE 3,2) y 1,7 (DE 0,5), respectivamente. Una mayor frecuencia de CFC (≥ 2 veces / semana) se asoció con un menor ICHC (ß: -0,29, IC 95%: -0,41 a -0,17, p <0,001), y con un menor ICG (ß: -0,02, IC 95%: -0,03 a -0,001, p <0,03). Los participantes con CFC ≥ 2 veces/semana tuvieron mayor riesgo de peor ICHC (OR: 1,31, IC 95%: 1,17-1,46, p <0,001), pero no de peor ICG (OR: 0,93 IC 95%: 0,83-1,03, p 0,194). Conclusiones: Hacer con mayor frecuencia CFC se asoció con una peor calidad de grasas en la dieta y especialmente con peor calidad de hidratos de carbono. Estos resultados destacan la importancia de la educación nutricional dirigida a los consumidores de CFC.Objective: To investigate the association between eating- away-from-home (EAFH) and a) the quality of dietary carbohydrate intake and b) the quality of fat intake. Material and methods: We assessed 19,371 participants in the SUN cohort who completed a validated baseline food frequency questionnaire. Quality indices of carbohydrate (CQI) and fat (FQI) were used. Multiple regression models were fitted to determine the association between the frequency of EAFH (4 categories) and both indices. Logistic regression analysis was used to assess the association between the frequency of EAFH and low CQI or FQI (<25th percentile). Results: Participants showed an average CQI and FQI of 11,3 (SD 3,2) and 1,7 (SD 0,5), respectively. A higher frequency of EAFH (≥ 2 times/week) was associated with a poorer CQI and a poorer FQI. For CQI, the adjusted mean difference was -0,29, 95%CI: -0,41, -0,17 (p for trend <0,001), and for FQI it was -0,02, 95%CI: -0,03, -0,001 (p for trend 0,03). Participants with a highest frequency (≥ 2 times/week) of EAFH had higher adjusted risk of a poorer CQI, (adjusted OR 1,31, 95%CI 1,17, 1,46, p for trend <0,001), but this habit (EAFH) was unrelated to FQI (adjusted OR 0,93, 95%CI: 0,83, 1,03, p for trend 0,194). Key findings: A higher frequency of EAFH was associated with a poorer quality of dietary fat, and particularly, dietary carbohohydrate. These findings highlight the importance of nutritional education addressed to consumers who frequently do out-of-home meals

    Review article of the current state of glaciers in the tropical Andes: a multi-century perspective on glacier evolution and climate change

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    The aim of this paper is to provide the community with a comprehensive overview of the studies of glaciers in the tropical Andes conducted in recent decades leading to the current status of the glaciers in the context of climate change. In terms of changes in surface area and length, we show that the glacier retreat in the tropical Andes over the last three decades is unprecedented since the maximum extension of the LIA (mid 17th–early 18th century). In terms of changes in mass balance, although there have been some sporadic gains on several glaciers, we show that the trend has been quite negative over the past 50 yr, with a mean mass balance deficit for glaciers in the tropical Andes that is slightly more negative than the computed global average. A break point in the trend appeared in the late 1970s with mean annual mass balance per year decreasing from −0.2m w.e. in the period 1964–1975 to −0.76m w.e. in the period 1976–2010. In addition, even if glaciers are currently retreating everywhere in the tropical Andes, it should be noted that as a percentage, this is much more pronounced on small glaciers at low altitudes that do not have a permanent accumulation zone, and which could disappear in the coming years/decades. Monthly mass balance measurements performed in Bolivia, Ecuador and Colombia showed that variability of the surface temperature of the Pacific Ocean is the main factor governing variability of the mass balance variability at the interannual to decadal time scale. Precipitation did not display a significant trend in the tropical Andes in the 20th century, and consequently cannot explain the glacier recession. On the other hand, temperature increased at a significant rate of 0.10◦Cdecade−1 in the last 70 yr. The higher frequency of El Nin ̃o events and changes in its spatial and temporal occurrence since the late 1970s together with a warming troposphere over the tropical Andes may thus explain much of the recent dramatic shrinkage of glaciers in this part of the world

    Setting a baseline for global urban virome surveillance in sewage

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    The rapid development of megacities, and their growing connectedness across the world is becoming a distinct driver for emerging disease outbreaks. Early detection of unusual disease emergence and spread should therefore include such cities as part of risk-based surveillance. A catch-all metagenomic sequencing approach of urban sewage could potentially provide an unbiased insight into the dynamics of viral pathogens circulating in a community irrespective of access to care, a potential which already has been proven for the surveillance of poliovirus. Here, we present a detailed characterization of sewage viromes from a snapshot of 81 high density urban areas across the globe, including in-depth assessment of potential biases, as a proof of concept for catch-all viral pathogen surveillance. We show the ability to detect a wide range of viruses and geographical and seasonal differences for specific viral groups. Our findings offer a cross-sectional baseline for further research in viral surveillance from urban sewage samples and place previous studies in a global perspective
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