419 research outputs found

    Morphometric differences in the grasshopper Cornops aquaticum (Bruner, 1906) from South America and South Africa

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    The semi-aquatic grasshopper Cornops aquaticum is native to South America and inhabits lowlands from southern Mexico to Central Argentina and Uruguay. It is host-specific to aquatic plants in the genera Eichhornia and Pontederia. A quarantine population has existed in South Africa for 10 y, and it is planned to release it there as a biological control agent of water hyacinth, E. crassipes. Various studies of C. aquaticum are coordinated under HICWA (www.mpil-ploen.mpg.de). This paper compares the morphometry of the release population and 11 native populations in South America. We tested four hypotheses: 1) South African and South American populations of C. aquaticum differ in morphology; 2) the South African laboratory population is more similar to other isolated populations in South America than to nonisolated populations; 3) morphology differs across sites; 4) morphology differs with host plant. South African populations differed from continental nonisolated populations, but not from continental isolated ones. Isolated populations presented smaller individuals than nonisolated, but there was also a change in male morphology: while in nonisolated populations male wing length was similar to their body length, in isolated populations, male wings were smaller than body length. Females were larger when on Eicchornia azurea than on E. crassipes, while males presented larger wings than their body on E. azurea, and similar lengths on E. crassipes. These morphological changes may have resulted from phenotypic plasticity, selection for small size, or because of a loss of genetic diversity in quantitative traits.Fil: Adis, Joachim. Institute for Limnology; AlemaniaFil: Sperber, Carlos F. Universidade Federal de Viçosa; BrasilFil: Brede, Edward G. Institute for Limnology; AlemaniaFil: Capello, Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Franceschini, Maria Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Hill, Martin. Rhodes University; SudáfricaFil: Lhano, Marcos G. Universidade Federal de Viçosa; BrasilFil: Marques, Marinê. A;z M.. Universidade Federal de Mato Grosso; BrasilFil: Nunes, Ana L.. Muséu Paraense Emílio Goeldi; BrasilFil: Polar, Perry. CAB International; Trinidad y Tobag

    A selfie nas paredes do museu: “O eu: entre o autorretrato e a selfie”

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    Este artigo resulta dos diálogos entre o autorretrato e a selfie enquanto fenômeno social da contemporaneidade propostos pela exposição “O eu: entre o autorretrato e a selfie”, buscando dar visibilidade ao acervo de um museu universitário e provocando a participação do público mediante um work in progress. O exame dessas interações dá base ao presente estudo que inclui uma revisão bibliográfica sobre os conceitos apresentados e propõe uma reflexão sobre as relações estabelecidas entre eles. Tais análises permitem um melhor entendimento da experiência com a selfie como um modelo de vasos comunicantes entre acervo, público e mídias sociais digitais, em direção a um museu conectado

    Activation of mTORC1 and c-Jun by Prohibitin1 loss in Schwann cells may link mitochondrial dysfunction to demyelination.

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    Schwann cell (SC) mitochondria are quickly emerging as an important regulator of myelin maintenance in the peripheral nervous system (PNS). However, the mechanisms underlying demyelination in the context of mitochondrial dysfunction in the PNS are incompletely understood. We recently showed that conditional ablation of the mitochondrial protein Prohibitin 1 (PHB1) in SCs causes a severe and fast progressing demyelinating peripheral neuropathy in mice, but the mechanism that causes failure of myelin maintenance remained unknown. Here, we report that mTORC1 and c-Jun are continuously activated in the absence of Phb1, likely as part of the SC response to mitochondrial damage. Moreover, we demonstrate that these pathways are involved in the demyelination process, and that inhibition of mTORC1 using rapamycin partially rescues the demyelinating pathology. Therefore, we propose that mTORC1 and c-Jun may play a critical role as executioners of demyelination in the context of perturbations to SC mitochondria

    Cytotoxic Activity of Triazole-Containing Alkyl ß-D-Glucopyranosides on a Human T-Cell Leukemia Cell Line

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    BACKGROUND: Simple glycoside surfactants represent a class of chemicals that are produced from renewable raw materials. They are considered to be environmentally safe and, therefore, are increasingly used as pharmaceuticals, detergents, and personal care products. Although they display low to moderate toxicity in cells in culture, the underlying mechanisms of surfactant-mediated cytotoxicity are poorly investigated. RESULTS: We synthesized a series of triazole-linked (fluoro)alkyl β-glucopyranosides using the copper-catalyzed azide-alkyne reaction, one of many popular click reactions that enable efficient preparation of structurally diverse compounds, and investigate the toxicity of this novel class of surfactant in the Jurkat cell line. Similar to other carbohydrate surfactants, the cytotoxicity of the triazole-linked alkyl β-glucopyranosides was low, with IC50 values decreasing from 1198 to 24 μM as the hydrophobic tail length increased from 8 to 16 carbons. The two alkyl β-glucopyranosides with the longest hydrophobic tails caused apoptosis by mechanisms involving mitochondrial depolarization and caspase-3 activation. CONCLUSIONS: Triazole-linked, glucose-based surfactants 4a-g and other carbohydrate surfactants may cause apoptosis, and not necrosis, at low micromolar concentrations via induction of the intrinsic apoptotic cascade; however, additional studies are needed to fully explore the molecular mechanisms of their toxicity. Graphical AbstractTriazole-linked, glucose-based surfactants cause apoptosis, and not necrosis, at low micromolar concentrations via induction of the intrinsic apoptotic cascade

    Longitudinal Study of a Human Drug-Induced Model of Autoantibody to Cytoplasmic Rods/Rings following HCV Therapy with Ribavirin and Interferon-alpha

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    Background: A novel pattern in the indirect immunofluorescence antinuclear antibody assay on HEp-2 cells (IIF-HEp-2) characterized by cytoplasmic rods and rings (RR) was reported in HCV patients, but stringent disease specificity studies and longitudinal analysis are lacking. We investigated the clinical significance of anti-RR in an HCV cohort with up to a 12-month treatment follow up.Methodology/Results: 597 patients (342 HCV, 55 HCV/HIV, 200 non-HCV) were screened and titered for anti-RR. Serial samples were available from 78 of 176 treated and 27 of 166 untreated patients. Anti-RR was detected in 14.1% of 342 HCV patients, 9.1% of 55 HCV/HIV, 3.4% of 29 Hepatitis B, and none of 171 non-HCV (p47% tested positive for anti-RR. the anti-RR titer generally increased with sustained treatment and remained high in 53% of patients. After treatment, anti-RR titer was negative in 41%. Non-responders to HCV therapy were 77% in anti-RR-positive versus 64% in anti-RR-negative patients. Response to treatment was not associated with anti-RR titer or the dynamics of anti-RR reactivity during and after treatment.Conclusions: the exquisite association of anti-RR reactivity with combined interferon-a/ribavirin therapy in HCV patients represents a unique model for drug-induced autoantibody generation in humans as demonstrated by the fact that a significant fraction of patients who have anti-RR during therapy becomes anti-RR-negative after completion of therapy.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Brazilian National Council for Research and Technological DevelopmentUniversidade Federal de São Paulo, Div Rheumatol, São Paulo, BrazilUniversidade Federal de São Paulo, Div Gastroenterol, São Paulo, BrazilUniversidade Federal de São Paulo, Div Infect Dis, São Paulo, BrazilFleury Med & Hlth Labs, Div Immunol, São Paulo, BrazilUniv Florida, Dept Oral Biol, Gainesville, FL 32610 USAUniversidade Federal de São Paulo, Div Rheumatol, São Paulo, BrazilUniversidade Federal de São Paulo, Div Gastroenterol, São Paulo, BrazilUniversidade Federal de São Paulo, Div Infect Dis, São Paulo, BrazilFAPESP: 2010/50710-6Brazilian National Council for Research and Technological Development: 305064/2011-8Web of Scienc

    Isobaric and Isochoric Heat Capacities of Imidazolium-Based and Pyrrolidinium-Based Ionic Liquids as Function of Temperature: Modeling of Isobaric Heat Capacity

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    International audienceThe isobaric and isochoric heat capacities of seven 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imides, two 1-alkyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imides, and two bis(1-alkyl-3-methylimidazolium) tetrathiocyanatocobaltates were determined at atmospheric pressure in the temperature range from 293.15 to 323.15 K. The isobaric heat capacities were determined by means of differential scanning calorimetry, whereas isochoric heat capacities were determined along with isothermal compressibilities indirectly by means of the acoustic method from the speed of sound and density measurements. Based on the experimental data, as expected, the isobaric heat capacity increases linearly with increasing alkyl chain length in the cation of 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imides and no odd and even carbon number effect is observed. After critical comparison of the obtained data with the available literature data, the most reliable values are recommended. It has been also shown that, although the COSMOthermX calculations underestimated the isobaric heat capacity values whatever the temperature and the ionic liquid structure, the approach used during this work may be applied to estimate physical properties of non-single-charged ions as well. Additionally, based on the speeds of sound the thermal conductivities were calculated using a modified Bridgman relation

    Confronting law affectively: encounters of a Patpong sex tourist

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    When considering spaces of sex-work such as Patpong in Bangkok, Thailand, the inclination is to be drawn into habitual debates concerning the legitimacy of sex-work and the clear objectification of sex-workers. While these concerns are valid and real, there are significant absences in terms of the theoretical mapping of the space, such as the affect of the presence of law, bodies, space and the sexual encounter itself. Law emerges as the most significant presence, since it both forms the transactional surface of Patpong and produces the confusion and revilement that results from the confluence of cold legal exchange with the tactile intimacy of the sexual encounter. This text explores the ethnographic space of Patpong in order to understand ways in which law’s transactional, effective surface is both embodied through subjectivication and spatially emplaced, yet also disrupted through the affective agency of the bodies and spaces it enfolds in order to produce this surface. This exploration will point to the limitations of law’s effective surface and suggest ways in which law might be located within a regime of affect, which returns the law to the body it subjectivises
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