2,941 research outputs found

    Predicting global geographical distribution of "Lolium rigidum" under climate change

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    “Lolium rigidum Gaud.” (vallico) es una de las malezas más extendidas y perjudiciales en los cultivos de cereales de invierno. Un modelo bioclimático para esta especie fue desarrollado utilizando CLIMEX. El modelo fue validado con los registros de esta especie en Estados Unidos y Oceanía y utilizado para predecir la distribución potencial global de “L. rigidum” bajo el clima actual y dos escenarios de cambio climático. Las proyección en virtud de las condiciones climáticas actuales indican que “L. rigidum” no ocupa todo el área disponible para su expansión. Considerando los escenarios climáticos futuros, el área potencial de expansión aumentará 3,79% y 5,06% bajo los escenarios moderado y extremo, respectivamente. La proyección del modelo mostró un avance gradual de “L. rigidum” en Norteamérica, Europa, Sudamérica y Asia, mientras que en África y Oceanía se prevé una regresión. Estos resultados proporcionan Los conocimientos necesarios para identificar y poner de relieve las posibles zonas de riesgo de invasión.“Lolium rigidum” Gaud. (rigid ryegrass) is one of the most extended and harmful weeds in winter cereal crops. A bioclimatic model for this species was developed using CLIMEX. The model was validated with records from North America and Oceania and used to assess the global potential distribution of “L. rigidum” under the current climate and under two climate change scenarios. The projection under current climate conditions indicated that “L. rigidum” does not occupy the full extent of the climatically suitable area available to it. Under future climate scenarios, the infested potential area will increase 3.79% in the low-emission CO2 scenario and 5.06% under the most extreme scenario. The model projection showed a gradual advance of rigid ryegrass in North America, Europe, South America and Asia, whilst in Africa and Oceania it indicated regression. These results provide the necessary knowledge for identifying and highlighting the potential invasion risk areas

    A new species of Websterinereis from the Gulf of California and redescription of Websterinereis foli (Fauvel, 1930) (Annelida, Nereididae)

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    A new species of Websterinereis Pettibone, 1971, W. pettiboneae sp. n. is described from La Paz Bay, Gulf of California, Mexico. This species is similar to W. foli (Fauvel, 1930) in the neuropodial falcigers shape, but can be separated by the tentacular cirri length, notopodial prechaetal lobe shape, and the size of the notopodial dorsal and ventral ligules on posterior parapodia. Websterinereis foli is redescribed based upon type material. Additional observations on the inter-annual density variation of W. pettiboneae sp. n. during a four-year study are also provided. A key to all species of Websterinereis is included

    tempo and mode of allopatric divergence in the weakly electric fish Sternopygus dariensis in the Isthmus of Panama

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    Spatial isolation is one of the main drivers of allopatric speciation, but the extent to which spatiallysegregated populations accumulate genetic differences relevant to speciation is not always clear. We used data from ultraconserved elements (UCEs) and whole mitochondrial genomes (i.e., mitogenomes) to explore genetic variation among allopatric populations of the weakly electric fish Sternopygus dariensis across the Isthmus of Panama. We found strong genetic divergence between eastern and western populations of S. dariensis. Over 77% of the UCE loci examined were differentially fixed between populations, and these loci appear to be distributed across the species’ genome. Population divergence occurred within the last 1.1 million years, perhaps due to global glaciation oscillations during the Pleistocene. Our results are consistent with a pattern of genetic differentiation under strict geographic isolation, and suggest the presence of incipient allopatric species within S. dariensis. Genetic divergence in S. dariensis likely occurred in situ, long after the closure of the Isthmus of Panama. Our study highlights the contribution of spatial isolation and vicariance to promoting rapid diversification in Neotropical freshwater fishes. The study of spatially-segregated populations within the Isthmus of Panama could reveal how genetic differences accumulate as allopatric speciation proceeds.Spatial isolation is one of the main drivers of allopatric speciation, but the extent to which spatiallysegregated populations accumulate genetic differences relevant to speciation is not always clear. We used data from ultraconserved elements (UCEs) and whole mitochondrial genomes (i.e., mitogenomes) to explore genetic variation among allopatric populations of the weakly electric fish Sternopygus dariensis across the Isthmus of Panama. We found strong genetic divergence between eastern and western populations of S. dariensis. Over 77% of the UCE loci examined were differentially fixed between populations, and these loci appear to be distributed across the species’ genome. Population divergence occurred within the last 1.1 million years, perhaps due to global glaciation oscillations during the Pleistocene. Our results are consistent with a pattern of genetic differentiation under strict geographic isolation, and suggest the presence of incipient allopatric species within S. dariensis. Genetic divergence in S. dariensis likely occurred in situ, long after the closure of the Isthmus of Panama. Our study highlights the contribution of spatial isolation and vicariance to promoting rapid diversification in Neotropical freshwater fishes. The study of spatially-segregated populations within the Isthmus of Panama could reveal how genetic differences accumulate as allopatric speciation proceeds

    Molecular diversity within clones of cv. Tannat (Vitis vinifera)

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    DNAs from 9 clones of cv. Tannat (Vitis vinifera) were analyzed at 89 microsatellite loci. Only one, VMCNg 1d12, showed a differential pattern that separated the clones in two groups. The statistical analysis of concentrations for aroma compounds from microvinifications also resulted in the same two groupings of clones. Many analyzed microsatellite loci amplified only one allele, implying that Tannat is a highly homozygous variety. For a given set of 15 microsatellites the level of homozygosity was 53 % for Tannat, in contrast to 6 % for Pinot, 20 % for both Cabernet Franc and Chardonnay and 33 % for Cabernet Sauvignon. We provide molecular data for Tannat, originating from southwestern France and nowadays becoming the emblematic cultivar of Uruguayan fine red wines. We also report a correlation between aroma-related compounds and molecular markers within clones of a cultivar.

    La salud reproductiva de los estudiantes de educación secundaria y media superior de San Luis Potosí

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    En el presente informe se muestran los resultados de la Encuesta de Salud Reproductiva de los estudiantes de educación secundaria y media superior de San Luis Potosí, en colaboración entre el CRIM y el Consejo Estatal de Población de San Luis Potosí.1. Algunos señalamientos sobre la salud reproductiva de los adolescentes en México. 2. Diseño muestral de la encuesta. 3. Educación sexual en la escuela. 4. Conocimiento sobre el sida. 5. Conocimiento sobre métodos anticonceptivos. 6. Edad media a la espermaquia y edad media a la menarquia. 7. Perspectivas de vida. 8. Recomendaciones

    Evidencias mineralógicas y geoquímicas de mezcla incompleta de magmas en la Sierra de las Cruces, Cinturón Volcánico Mexicano

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    Received: 19/05/2011 / Accepted: 12/04/2013.Pliocene – Pleistocene lava flows, mainly of dacitic composition, are exposed in the Sierra de las Cruces (SC) volcanic range within the Mexican Volcanic Belt (MVB). SC volcanic rocks are porphyritic, generally containing an assemblage of plagioclase + amphibole + orthopyroxene ± clinopyroxene ± quartz ± Fe-Ti oxides. Most of them exhibit diverse mineralogical and geochemical features that attest a magma mixing and mingling processes with concomitant fractional crystallization in which a small volume of hot andesite magma injects into dacitic magma. Both rock types are probably derived from partial melting of continental crust at different levels. The evidences of magma mixing and mingling include: (a) normal and sieved plagioclases in the same sample, rounded and embayed crystals, and armoured rims over the dissolved crystal surfaces; (b) subrounded, vesicular magmatic enclaves, ranging from a few millimeters to ~20 centimeters in size, with plagioclase + orthopyroxene + amphibole + quartz ± olivine ± Fe-Ti-oxides assemblage; (c) mineral chemistry evidence such as crystals with reaction rims or heterogeneous plagioclase compositions (inverse and oscillatory zoning or normally and inversely zoned crystals) in the same sample; and (d) elemental geochemical variations and trace-element ratio more akin to magma mixing and to some extent diffusion process. These andesitic enclaves could be considered as portions of the intermediate magma that did not mix completely (mingling) with the felsic host lavas, confirming the major role of magma mixing and mingling processes in the overall evolution of the MVB.En la Sierra de las Cruces (SC), Cinturón Volcánico Mexicano (CVM), se encuentran expuestos flujos de lava, principalmente de composición dacítica, del Plioceno-Pleistoceno. Las rocas volcánicas de la SC son de textura porfirítica, conteniendo plagioclasa + anfibol + ortopiroxeno ± clinopiroxeno ± cuarzo ± óxidos de Fe-Ti. La mayor parte de ellas exhiben diversas características que indican un proceso de mezcla incompleta de magmas, con una cristalización fraccionada concomitante, en la que un pequeño volumen de un magma andesítico caliente es inyectado a un magma dacítico. Es probable que ambos tipos de roca se hayan generado por fusión parcial a diferentes niveles de la corteza continental. Las evidencias de la mezcla incompleta de magmas incluyen: (a) plagioclasas con texturas normal y anubarrada en la misma muestra, cristales redondeados y corroídos, y bordes de reacción en superficies de cristal disueltas; (b) enclaves magmáticos subredondeados y vesiculares, que ocurren en dimensiones de un pocos milímetros a ~20 centímetros de diámetro, con plagioclasa + ortopiroxeno + anfíbol + cuarzo ± olivino ± óxidos de Fe-Ti; (c) química de minerales, que incluye cristales con bordes de reacción o plagioclasas de composición heterogénea (zonación inversa y oscilatoria o cristales con zonación normal e inversa) en la misma muestra; y (d) variaciones geoquímicas de elementos y relaciones de elementos traza explicables por una mezcla de magmas y por un proceso de difusión. Los enclaves andesíticos podrían considerarse como porciones de magma intermedio que no se mezcló con los líquidos dacíticos receptores, lo que confirma la importancia de los procesos de mezcla incompleta de magmas en la evolución magmática del CVM.Universidad Autónoma de Nuevo LeónDepto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

    Mesozooplankton distribution, production and respiration in the global ocean.

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    Mesozooplankton biomass, abundance and mass-specific physiological rates as well as community production and respiration in the upper 2000 m were assessed from samples collected during the Malaspina circumnavigation expedition (~35ºN-40ºS) using an image-based analysis system (IBS). Equations relating metabolic rates, temperature, and body weight, were developed according to temperature ranges found at the different ocean regions and depth layers. High abundance and biomass were observed in the epipelagic zone and decreasing with depth as expected. However, high biomass was also found beyond 1000 m related to the colder and productive waters of the eastern regions of the Indian and Pacific Oceans. Specific growth and respiration rates followed a similar pattern and were highly correlated with temperature (r2=0.835 and 0.806 , respectively). Therefore, higher values were observed in the tropical and subtropical zones as the effect of higher temperature. Community production and respiration were considerably higher in the epipelagic layer, matching the distribution of biomass, with high values below 1000 m in the eastern Pacific/Indian Oceans. Global metabolism assessed through the IBS was similar to previous results based on data review.MALASPINA (CSD2008-00077

    Article Germacrone Derivatives as new Insecticidal and Acaricidal Compounds: A Structure-Activity Relationship

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    The supplementary material related to this article includes NMR spectra of new compounds is available online at https://www.mdpi.com/1420-3049/24/16/2898/s1.Currently, the use of synthetic pesticides is the main method of plant protection applied in agri- and horticulture. However, its excessive use leads to the development of pesticide resistance, a contamination of the environment, toxicity to non-target organisms, and risks for human health. With the ultimate aim of contributing to the develop of a more sustainable pest management, we used the natural product germacrone (compound 1), reported to possess significant insecticidal activity, as starting material for the generation of molecular diversity (2–24). Some of the generated derivatives are natural compounds, such as 1,10-epoxygermacrone (2), 4,5-epoxygermacrone (3), gajutsulactone A (7), germacrol (11), isogermacrone (14), 9-hydroxyeudesma-3,7(11)dien-6-one (19), eudesma-4,7(11),dien-8-one (20), eudesma-3,7(11)-dien-8-one (21) and eudesma-4(15),7(11)-dien-8-one (22). Compounds, 7,11-9,10-diepoxigermacr-4,5-en-8-ol (17), 7,11-epoxieudesma-4,7(11)-dien-8-one (23) and 7,11-epoxieudesma-3,7(11)-dien-8-one (24) are described for the first time. The biocidal activity of most of these compounds was assayed against the tick Hyalomma lusitanicum. The acaricidal effects of compound 24 were four times higher than that of germacrone (1). Compound 2 is an insect antifeedant a thousand times more potent than germacrone against Rhopalosiphum padi, which makes this substance a promising selective antifeedant against this cereal pest.This research was funded by Grant CTQ-2015-64049-C3-3-R/CTQ2015-64049-C3-1-R; MINISTERIO DE ECONOMÍA Y COMPETITIVIDAD, Spain (MINECO/FEDER)

    Dolor crónico: relación con sintomatología prefrontal y estrés percibido

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    ABSTRACT Objective: The quality of perceived stress coping in chronic pain is related to the performance of the prefrontal cortex as the main structure of control and coordination of superior behavior control. The present study explores the presence of prefrontal symptomatology, in the form of problems to manage cognition, emotions and behavior, and perceived stress in a sample of people suffering from chronic pain. Material and methods: We studied 78 participants with a diagnosis of chronic pain ranging in age from 27 to 81 years (mean 54.2 and d.t 13.4). Sociodemographic and clinical variables were analyzed together with the results in the 11-item Short Brief Pain Questionnaire (CBD) to assess the intensity and interference of pain, the Prefrontal Symptom Inventory (ISP), both in its complete version of 46 items and in the abbreviated of 20, and the 10-itme Perceived Scale of Perceived Stress (EEP). Results and discussion: Significant correlations between the prefrontal symptomatology and the intensity (r = 0.32) and the interference (r = 0.53) of the pain, as well as between the stress and the interference of the pain in the mood (r = 0.36). People report more painful feelings when they refer more cognitive and emotional management problems surrounding the environment. The general interference of pain is related to more motivational and attention problems, while the interference that the pain produces in the mood also increases the problems with executive and emotional control. A preliminary structural equation explaining the effect is proposed. Conclusion: The data suggest that the stress perceived by people with chronic pain depends on the inability of the prefrontal cortex to cope with a changing or threatening situation and this problem is fed back over and over as the person is less able to cope with the environment. Therefore, comprehensive treatment of chronic pain should include psychological interventions focused on coping with stress and cognitive optimization of skills related to prefrontal functioning.RESUMEN Objetivo: La calidad del afrontamiento del estrés percibido en el dolor crónico está relacionada con el rendimiento de la corteza prefrontal como estructura principal de control y coordinación de control superior de la conducta. El presente trabajo estudia la presencia de sintomatología prefrontal, en forma de problemas para gestionar la cognición, las emociones y el comportamiento, y de estrés percibido en una muestra de personas que sufren dolor crónico. Material y métodos: Se estudiaron 78 participantes con diagnóstico de dolor crónico con edades comprendidas entre 27 y 81 años (media 54,2 y d.t. 13,4). Se analizaron variables sociodemográficas y clínicas junto con los resultados en el Cuestionario Breve de Dolor (CBD) abreviado de 11 ítems para valorar la intensidad e interferencia de dolor, el Inventario de Síntomas Prefrontales (ISP), tanto en su versión completa de 46 ítems como en la abreviada de 20, y la Escala de Estrés Percibido (EEP) abreviada de 10 ítems. Resultados y discusión: Aparecen correlaciones significativas entre la sintomatología prefrontal y la intensidad (r = 0,32) y la interferencia (r = 0,53) del dolor, así como entre el estrés y la interferencia del dolor en el estado del ánimo (r = 0,36). Las personas declaran más sensación dolorosa cuando refieren más problemas de gestión cognitiva y emocional del entorno que las rodea. La interferencia general del dolor se relaciona con más problemas motivacionales y de atención, mientras que la interferencia que el dolor produce en el estado del ánimo incrementa, además, los problemas con el control ejecutivo y emocional. Se propone una ecuación estructural preliminar explicativa del efecto. Conclusión: Los datos sugieren que el estrés percibido por las personas con dolor crónico depende de la incapacidad de la corteza prefrontal para afrontar una situación cambiante o amenazante, y este problema se retroalimenta una y otra vez al ser la persona cada vez menos capaz de afrontar el ambiente. Por tanto, el tratamiento integral del dolor crónico debe incluir intervenciones psicológicas centradas en el afrontamiento del estrés y la optimización cognitiva de las habilidades relacionadas con el funcionamiento prefrontal
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