42 research outputs found

    Toxoplasma gondii-skeletal muscle cells interaction increases lipid droplet biogenesis and positively modulates the production of IL-12, IFN-g and PGE2

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    Background: The interest in the mechanisms involved in Toxoplasma gondii lipid acquisition has steadily increased during the past few decades, but it remains not completely understood. Here, we investigated the biogenesis and the fate of lipid droplets (LD) of skeletal muscle cells (SkMC) during their interaction with T. gondii by confocal and electron microscopy. We also evaluated whether infected SkMC modulates the production of prostaglandin E2 (PGE2), cytokines interleukin-12 (IL-12) and interferon-gamma (INF-g), and also the cyclooxygenase-2 (COX-2) gene induction. Methods: Primary culture of skeletal muscle cells were infected with tachyzoites of T. gondii and analysed by confocal microscopy for observation of LD. Ultrastructural cytochemistry was also used for lipid and sarcoplasmatic reticulum (SR) detection. Dosage of cytokines (IL-12 and INF-g) by ELISA technique and enzyme-linked immunoassay (EIA) for PGE2 measurement were employed. The COX-2 gene expression analysis was performed by real time reverse transcriptase polymerase chain reaction (qRT-PCR). Results: We demonstrated that T. gondii infection of SkMC leads to increase in LD number and area in a time course dependent manner. Moreover, the ultrastructural analysis demonstrated that SR and LD are in direct contact with parasitophorous vacuole membrane (PVM), within the vacuolar matrix, around it and interacting directly with the membrane of parasite, indicating that LD are recruited and deliver their content inside the parasitophorous vacuole (PV) in T. gondii-infected SkMC. We also observed a positive modulation of the production of IL-12 and IFN-g, increase of COX-2 mRNA levels in the first hour of T. gondii-SkMC interaction and an increase of prostaglandin E2 (PGE2) synthesis from 6 h up to 48 h of infection. Conclusions: Taken together, the close association between SR and LD with PV could represent a source of lipids as well as other nutrients for the parasite survival, and together with the increased levels of IL-12, INF-g and inflammatory indicators PGE2 and COX-2 might contribute to the establishment and maintenance of chronic phase of the T. gondii infection in muscle cell

    Bioactivity of neem oil on Alphitobius diaperinus (Coleoptera: Tenebrionidae) in stored peanut seeds

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    Amanda da Silva Lira: Atualmente é professora efetiva do Departamento de Estatística e Ciências Atuariais na Universidade Federal de Sergipe UFS (2011)Propôs-se, neste trabalho, avaliar a bioatividade do óleo de nim sobre Alphitobius diaperinus, em sementes armazenadas. Sementes de amendoim cultivar BRS Havana foram tratadas com óleo de nim nas concentrações de 0,0; 1,0; 2,0; 3,0 e 4,0% (volume/massa de sementes) e mantidas em bandejas durante 24 h. Cinquenta gramas de sementes foram colocados em recipientes plásticos e infestados com 20 insetos adultos de A. diaperinus. Avaliaram-se, aos 30, 60, 90 e 120 dias de armazenamento, a mortalidade, o número de descendentes (larvas, pupas e adultos) e o número de sementes perfuradas. Para análise de variância dos dados utilizou-se o teste de Friedman (p ≤ 0.05), sendo a comparação das médias realizada pelo teste de Student Newman Keuls (p ≤ 0.05). Calculou-se, também, a eficiência do produto pelo método de Henderson & Tilton (1955). Eficiência do óleo de nim sobre a mortalidade de A. diaperinus acima de 74,92% foi observada a partir dos 90 dias do armazenamento, para as concentrações de 3 e 4%; entretanto, o produto conferiu proteção às sementes de amendoim, em todas as concentrações, nos períodos estudados, visto que afetou todos os descendentes de A. diaperinus da geração F1. _________________________________________________________________________________________ ABSTRACT: This work aimed to evaluate the bioactivity of neem oil on Alphitobius diaperinus, in stored seed. Peanuts seeds, cultivar BRS Havana, were treated with neem oil at concentrations of 0.0, 1.0, 2.0, 3.0 and 4.0% (volume/weight) and kept in trays for 24 h. Fifty grams of seeds were put in plastic containers and infested with 20 adult insects of A. diaperinus. The mortality, the offspring number (larvae, pupae and adults) and the number of punched seeds were evaluated at 30, 60, 90 and 120 days of storage. For variance analysis of data, Friedman test (p £ 0.05) was used. Student Newman Keuls test (p £ 0.05) was used for comparison of means. The product efficiency was also analysed by using Henderson & Tilton (1955) method. Neem oil efficiency on the mortality of A. diaperinus above 74.92% was observed from 90 days of storing for concentrations of 3 and 4%. However, the neem oil conferred protection to peanut seeds in all concentrations and studied periods, by affecting all offspring of A. diaperinus of the F1 generation

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

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    Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ

    Surface roughness of acrylic resins processed by microwave energy and polished by mechanical and chemical process

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    The aim of this study was to evaluate the influence of polymerization methods (microwave energy - MW, and water bath - WB) and polishing techniques (chemical - C and mechanical - M) on the surface roughness of one heat-polymerized acylic resin (Vipi-Cril). Forty acrylic resin disk-shaped samples were made according to ADA specification n° 12. Half of samples were processed by microwave energy (500W for 3 minutes), and the other half by water bath (74±1 °C for 9 hours). After deflasking, the samples were trimmed with a sequence of abrasive aluminum oxide sandpapers of different grades (180, 220 and 400) and divided in 4 groups according to polymerization methods and polishing techniques: G1: MW+CP, G2: MW+MP, G3: WB+CP and G4: WB+MP. Surface roughness values were measured using a Surfcorder SE 1700 rugosimeter (Kosaka Laboratory Ltd, Kosaka, Japan). Mann-Whitney test (p=.05) indicated significant differences between polishing methods processed by microwave energy (p= .0018), and between polishing methods processing by water bath (p= .0002). Samples processed by both methods (water bath or microwave energy) showed smoother surfaces when polished by mechanical polishing method, and polymerization methods did not influence in surface roughness
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