121 research outputs found

    Effect of Different Parameters (Treatment Administration Mode, Concentration and Phenological Weed Stage) on Thymbra capitata L. Essential Oil Herbicidal Activity

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    The essential oil (EO) of Thymbra capitata has been demonstrated to possess herbicidal activity and could be used as an alternative to synthetic herbicides with reduced persistence in soil and new mode of action. Nevertheless, it is necessary to determine the adequate doses for its use, the proper way for its application and the best phenological stage of weeds and crops in which the EO should be applied to obtain maximum efficacy against weeds without compromising crop production. In this work, T. capitata EO was tested at three different concentrations against weeds grown from a citrus orchard soil seedbank untreated with herbicides and against three important weed species grown in substrate to determine the efficacy of the concentrations on different weed species. All experiments were carried out under greenhouse conditions. To find out the best way for applying the EO, it was applied by irrigation and by spraying on the targeted weeds, and to verify the influence of timing, it was tested on Lolium rigidum at two different phenological stages and on wheat at a later phenological stage than weeds. The highest concentration tested (12 μL·mL−1) showed the best performance to control weeds. The more effective mode of application was by spraying on dicotyledons and by irrigation on monocotyledons at the earliest phenological stage. T. capitata EO was phytotoxic for wheat. More trials in different crops are needed to determine the best conditions for its use

    Herbicidal activity of essential oils extracted from different Mediterranean species against Echinochloa crus galli

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    Weed infestation in agricultural fields can cause huge economic losses and low-quality crop yields. Echinochloa crus-galli (L.) P.Beauv. (barnyardgrass) is one of the greatest yields limiting weeds in rice cultivation systems. It is a cosmopolitan weed in both temperate and tropical regions and is reported as a weed in 36 different crops in 61 countries. The success of this weed may be attributed to the production of large numbers of small, easily dispersed seeds per plant, possession of seed dormancy, rapid development and ability to flower under a wide range of photoperiods, and relative resistance of mature plants to herbicide sprays. Thus, the best way to control barnyardgrass in an environmentally acceptable and sustainable approach is to develop eco-friendly and effective alternative means based on natural allelochemicals. Among the natural plant products, essential oils (EOs) constitute an important group. EOs may help reducing the use of synthetic herbicides and lead to less pollution and more safe agricultural products. Recently, the interest in exploring EOs with phytotoxic effects from aromatic plants for weed control has increased tremendously, because they do not persist in soil and do not leach into ground water. EOs extracted from Thymbra capitata (L.) Cav.; Mentha x piperita L.; and Santolina chamaecyparissus L. were reported to reduce the emergence and seedling growth of many weeds. The present investigation allows for a more detailed insight into the herbicidal activity of the previously mentioned EOs during spray foliar and irrigation application in post-emergence on E. crus-galli plants. T. capitata M. piperita and S. chamaecyparissus EOs were purchased from “Bordas Chinchurreta”, “Sigma-Aldrich” and and “Aromas de Ademuz”, respectively. Soil for the experiments was collected from the topsoil of a citrus field not treated with herbicides (Valencia, Spain), that was air-dried and sieved at 1 cm. E.crus-galli seeds were purchased from Herbiseed (England), and germinated in a germination-growth chamber at 30 ± 0.1 °C, 16 h in light and 20 ± 0.1 °C, 8 h in dark. Once the seedlings of E.crus-galli emerged, they were placed on pots (8x8x7 cm) filled with 2 cm of perlite at the bottom and 5 cm of the collected soil. Ten pots per treatment were prepared and placed in the greenhouse. In order to find the most effective dose of EOs and its adequate mode of application, different concentrations were used: 12, 16 and 20 µL/mL for Mentha and Santolina EOs and 4, 8 and 12 µL/mL for Thymbra EO. Fitoil was used as emulsifier at a concentration of 0.05% (v/v). Plants of barnyardgrass were treated at two-leaf stage by irrigating and spraying mode of application. To monitor the experiments, photos were taken after 24, 48 and 72 hours; and then once a week. The photos were processed with Digimizer software to obtain different data: efficacy of the treatment, level of damage, height of plants, weed plant fresh and dry weight

    Adaptability of invasive plants to climate change

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    [EN] Climate change represents one of the greatest environmental challenges of the 21st century, accentuated by deforestation and the degradation of habitats. Changes in vital aspects such as temperature, the amount and distribution of rainfall or the frequency of extreme meteorological phenomena will probably negatively affect ecosystems. The possibilities of invasion will predictably increase, being endemic species especially vulnerable to the effects of climate change. Invasive species are extremely adaptable to climate variability, as evidenced by their current large latitudinal ranges. Generally, invasive plants also have rapid dispersal characteristics, allowing them to vary their ranges in response to changing climatic conditions rapidly. As a result, these species could become more dominant in many areas under changing climatic conditions. In many situations, the environmental stress generated by climate change and invasive plants are synergistic: invasive species can exacerbate the impacts of climate change on ecosystems, and in the same way, climate change can allow new invasions.S.G-O acknowledges a 'Margarita Salas' postdoctoral contract from Universitat Politècnica de València and the Spanish Ministry of Universities, supported by the European Union - Next Generation fundsGonzález-Orenga, S.; Boscaiu, M.; Verdeguer Sancho, MM.; Sánchez-Moreiras, AM.; González, L.; Vicente, O. (2022). Adaptability of invasive plants to climate change. AgroLife Scientific Journal (Online). 11(2):58-65. https://doi.org/10.17930/AGL202227586511

    Actas Portuguesas de Horticultura

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    La producción de estátice en el sur de la Comunidad Valenciana es de gran relevancia en la floricultura. Se trata de una especie halotolerante en la que, hoy por hoy, para el manejo de su fertirrigación se utilizan aguas de baja salinidad en la que se incorporan elevados contenidos de nutrientes. Tanto el hecho de que se consigan elevados rendimientos de calidad como el coste menor que suponen los fertilizantes respecto a los del resto de los insumos de cultivo, explican que esta práctica se haya establecido. Se sabe, sin embargo, que el estátice es una planta poco exigente en nutrientes minerales, por lo que son de suponer elevadas pérdidas de los mismos por lixiviación, que no son permisibles desde una perspectiva de sostenibilidad. Minimizar los aportes minerales sin que se produzcan mermas ni en el rendimiento ni en la calidad de la cosecha es un claro objetivo a perseguir. El periodo de recolección se inicia a final de octubre y es continuo hasta final de mayo con variaciones estacionales de las tasas de producción. Este trabajo se plantea para conocer los efectos de la reducción en un 50% de los aportes minerales sobre el rendimiento y la calidad de la cosecha a lo largo del ciclo de cultivo. Para ello, en un mismo invernadero y a lo largo de todo un ciclo de cultivo, se ha llevado el seguimiento y comparación de la producción de tallos florales de dos poblaciones de Limonium sinuatum cv. Duel Violet, con la misma fecha de plantación. Para cada uno de los tratamientos, se han determinado semanalmente tanto la cantidad (número de tallos florales, pesos fresco y seco) como la calidad (longitud de los tallos, de las panículas, relaciones peso seco vs peso fresco) de los tallos florales cosechados. Paralelamente, se han obtenido relaciones de la biomasa producida con respecto a la radiación interceptada y la integral térmica. No se muestran diferencias cualitativas entre ambos tratamientos en casi todo el periodo de cultivo. Cuantitativamente, desde noviembre hasta marzo las respuestas de los tratamientos son similares, dependiendo el rendimiento tanto de la radiación interceptada como de la integral térmica, sin embargo, en primavera, con temperaturas medias elevadas y fotoperiodos más largos que revierten en mayores tasas de producción, la menor aportación mineral resulta en un ligero descenso del rendimiento en unidades totales al final del cultivo, que la planta compensa aumentando el peso de los tallos florales, y la calidad de los mismos

    Herbicidal Potential of the Natural Compounds Carvacrol, Thymol, Eugenol, p-Cymene, Citral and Pelargonic Acid in Field Conditions: Indications for Better Performance

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    In recent years, interest in natural products with herbicidal activity as new tools for integrated weed management has increased. The European Union is demanding a reduction in the number of herbicides used, forbidding use of the most toxic ones, despite the problem of weed resistance increasing. Pelargonic acid (PA) is the only natural herbicide available in Spain. In this work, two field assays were performed with the natural compounds carvacrol (CAR), citral (CIT), eugenol (EUG), thymol (THY), p-cymene (P-CYM), (PA), and the combination of PA with CIT-all except P-CYM formulated by Seipasa-to test their herbicidal efficacy in real conditions. They were compared with commercial PA, glyphosate (GLY) and oxyfluorfen (OXY). In both experiments, GLY achieved the best weed control. Considering the natural herbicides, PA formulated by Seipasa and PA plus CIT were the most effective. From both experiments, some conclusions can be extracted for better herbicidal performance of natural products: (1) use products on sensitive weed species, (2) treat weeds at earlier phenological stages, (3) find the active doses in field conditions, (4) cover weeds well when treating, (5) ensure adequate formulation of products, and (6) develop a strategy for correct application

    PPARγ contributes to PKM2 and HK2 expression in fatty liver

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    Rapidly proliferating cells promote glycolysis in aerobic conditions, to increase growth rate. Expression of specific glycolytic enzymes, namely pyruvate kinase M2 and hexokinase 2, concurs to this metabolic adaptation, as their kinetics and intracellular localization favour biosynthetic processes required for cell proliferation. Intracellular factors regulating their selective expression remain largely unknown. Here we show that the peroxisome proliferator-activated receptor gamma transcription factor and nuclear hormone receptor contributes to selective pyruvate kinase M2 and hexokinase 2 gene expression in PTEN-null fatty liver. Peroxisome proliferator-activated receptor gamma expression, liver steatosis, shift to aerobic glycolysis and tumorigenesis are under the control of the Akt2 kinase in PTEN-null mouse livers. Peroxisome proliferator-activated receptor gamma binds to hexokinase 2 and pyruvate kinase M promoters to activate transcription. In vivo rescue of peroxisome proliferator-activated receptor gamma activity causes liver steatosis, hypertrophy and hyperplasia. Our data suggest that therapies with the insulin-sensitizing agents and peroxisome proliferator-activated receptor gamma agonists, thiazolidinediones, may have opposite outcomes depending on the nutritional or genetic origins of liver steatosis

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Inhibitor of apoptosis proteins, NAIP, cIAP1 and cIAP2 expression during macrophage differentiation and M1/M2 polarization

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    Monocytes and macrophages constitute the first line of defense of the immune system against external pathogens. Macrophages have a highly plastic phenotype depending on environmental conditions; the extremes of this phenotypic spectrum are a pro-inflammatory defensive role (M1 phenotype) and an anti-inflammatory tissue-repair one (M2 phenotype). The Inhibitor of Apoptosis (IAP) proteins have important roles in the regulation of several cellular processes, including innate and adaptive immunity. In this study we have analyzed the differential expression of the IAPs, NAIP, cIAP1 and cIAP2, during macrophage differentiation and polarization into M1 or M2. In polarized THP-1 cells and primary human macrophages, NAIP is abundantly expressed in M2 macrophages, while cIAP1 and cIAP2 show an inverse pattern of expression in polarized macrophages, with elevated expression levels of cIAP1 in M2 and cIAP2 preferentially expressed in M1. Interestingly, treatment with the IAP antagonist SMC-LCL161, induced the upregulation of NAIP in M2, the downregulation of cIAP1 in M1 and M2 and an induction of cIAP2 in M1 macrophages.This work was supported by Universidad de Granada, Plan Propio 2015;#P3B: FAM, VMC (http://investigacion.ugr.es/pages/planpropio/2015/ resoluciones/p3b_def_28072015); Universidad de Granada CEI BioTic;#CAEP2-84: VMC (http:// biotic.ugr.es/pages/resolucionprovisional enseaanzapractica22demayo/!); and Canadian nstitutes of Health Research;#231421, #318176, #361847: STB, ECL, RK (http://www.cihr-irsc.gc. ca/e/193.html). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
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