925 research outputs found

    Colour variation in signal crayfish Pacifastacus leniusculus

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    External colouration in animals depends on the interaction of several different factors including the genetics and epigenetics processes that underlie the colour expression, the mechanisms of colour perception, and the general mechanisms controlling colour evolution and function. Among all, camouflage from predators and conspicuousness are of particular interest since pose animal to choose between opposite adjustment in colouration. The external colouration of crustaceans is mainly due to the accumulation of carotenoids in the exoskeleton and the epidermal layer, and the trade-off between camouflage and communication had lead to a variety of responses, involving signal partitioning, spectral sensibility, changing colouration or signalling behaviour. Here, we used digital images to explore intrapopulation variability of the external colouration of Pacifastacus leniusculus among body regions within an individual and between sexes. We found that i) ventral colouration of claws are more saturated and brilliant than upperparts, ii) males express a more saturated and brightness colouration than females, especially on the lower portion of claws, iii) colour intensity and brightness increases with size differently in different body regions, and iv) brightness is more variable in males than in females. All the above patterns support the hypothesis that colour in this species could be the result of a compromise between camouflage from predators and conspicuousness for communication. The results of this study suggest that carotenoid might have something to do with intraspecific communication and perform more complex functions than that of a simple pigment

    A Prospective Study Evaluating IOP Changes after Switching from a Therapy with Prostaglandin Eye Drops Containing Preservatives to Nonpreserved Tafluprost in Glaucoma Patients

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    Purpose. To compare the ocular hypotensive effect of tafluprost with prostaglandin analogues (PGAs) in glaucoma patients. Methods. 89 primary open-angle glaucoma patients treated with bimatoprost, latanoprost, or travoprost for at least 3 months complaining for ocular discomfort were switched to tafluprost. IOP was assessed at baseline and 3 months after switching the therapy by daily curve. Primary outcome was to compare the mean daily IOP of tafluprost with PGAs. Results. The mean daily IOP was 16 ± 2.1 and 16.6 ± 2.0 mm Hg at baseline and after switching to tafluprost, respectively (P > 0.05). When analysis was carried out between tafluprost and each previous PGAs, the comparison between latanoprost and tafluprost and travoprost and tafluprost did not show any statistically significant difference in mean daily IOP and at each time point. The comparison between bimatoprost and tafluprost showed a statistically significant difference in mean daily IOP (P < 0.05) and at each time point (P < 0.05). Conclusions. After 3 months of switching tafluprost showed an overall IOP lowering effect similar to others PGAs. When each PGA was compared with tafluprost, bimatoprost showed to provide a statistically significant additional IOP lowering effect

    Synergistic effect of gefitinib and rofecoxib in mesothelioma cells

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    <p>Abstract</p> <p>Background</p> <p>Malignant mesothelioma (MM) is an aggressive tumor that is resistant to conventional modes of treatment with chemotherapy, surgery or radiation. Research into the molecular pathways involved in the development of MM should yield information that will guide therapeutic decisions. Epidermal growth factor receptor (EGFR) and cyclooxygenase-2 (COX-2) are involved in the carcinogenesis of MM. Combination of COX-2 and EGFR inhibitors, therefore, could be an effective strategy for reducing cell growth in those lines expressing the two molecular markers.</p> <p>Results</p> <p>In order to verify the effect of COX-2 and EGFR inhibitors, five MM cell lines NCI-2452, MPP89, Ist-Mes-1, Ist-Mes-2 and MSTO-211 were characterized for COX-2 and EGFR and then treated with respective inhibitors (rofecoxib and gefitinib) alone and in combination. Only MPP89, Ist-Mes-1 and Ist-Mes-2 were sensitive to rofecoxib and showed growth-inhibition upon gefitinib treatment. The combination of two drugs demonstrated synergistic effects on cell killing only in Ist-Mes-2, the cell line that was more sensitive to gefitinib and rofecoxib alone. Down-regulation of COX-2, EGFR, p-EGFR and up-regulation of p21 and p27 were found in Ist-Mes-2, after treatment with single agents and in combination. In contrast, association of two drugs resulted in antagonistic effect in Ist-Mes-1 and MPP89. In these cell lines after rofecoxib exposition, only an evident reduction of p-AKT was observed. No change in p-AKT in Ist-Mes-1 and MPP89 was observed after treatment with gefitinib alone and in combination with rofecoxib.</p> <p>Conclusions</p> <p>Gefitinib and rofecoxib exert cell type-specific effects that vary between different MM cells. Total EGFR expression and downstream signalling does not correlate with gefitinib sensitivity. These data suggest that the effect of gefitinib can be potentiated by rofecoxib in MM cell lines where AKT is not activated.</p

    Ética, pesquisa e imagem de povos indígenas

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    Este artigo explora dois temas principais: a) a centralidade das imagens na cultura contemporânea b) e o candente debate sobre questões éticas em pesquisa a partir da aplicação do modelo biomédico às ciências humanas. Ele explora a ética e a pesquisa em educação com foco na legislação que regulamenta a pesquisa com povos indígenas. O texto ainda argumenta que a reiteração de certas imagens constitui uma poderosa iconografia sobre os povos indígenas, a qual contribui para naturalizar certas representações sobre eles. Finalmente, o artigo também defende que seria oportuno garantir práticas éticas pluralistas (de mudança e ética circunstancial de pesquisa em educação) em vez de considerar um conjunto de princípios e condutas éticas predeterminado.This paper explores two main topics: a) the centrality of images in the contemporary culture, b) and the burning debate on ethical issues in research concerning the application of the biomedical model to the human sciences. It explores ethics and research in education focusing on the legislation that regulates the research with indigenous people. The paper argues that the reiteration of certain images constitutes a powerful iconography on indigenous peoples, which contributes to naturalize certain representations about them. Finally, this paper also advocates that would be appropriate ensure pluralist ethical practices (of changing and circumstantial ethics of research in education) rather than to consider a set of pre-given ethical principles and conducts

    Considerations on cultural studies in Brazil

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    A partir de uma revisão sobre as articulações entre os Estudos Culturais e as teorizações das áreas da Comunicação Social, Antropologia, Ciências Sociais, Teoria Literária e Educação no Brasil, coloca-se em destaque a produtividade acadêmica de conceitos, perspectivas e modos de pesquisa. O estudo envolveu: (a) ampla varredura nos principais periódicos internacionais de Estudos Culturais; (b) pesquisa no Google Acadêmico e em outras plataformas específicas; (c) investigação de filiações institucionais, grupos de pesquisa, currículos Lattes e, eventualmente, entrevistas disponibilizadas online. Finaliza-se este texto apresentando apontamentos político-acadêmicos relativos aos estudos realizados no Brasil em sua articulação com os Estudos Culturais latino-americanos.From a review of articulations between Cultural Studies and theories of social communication, anthropology, social sciences, literary theory and education in Brazil, the academic production of concepts, perspectives and approaches in research is highlighted. The study involved: (a) a comprehensive search on the major international journals of Cultural Studies; (b) a search on Google Scholar and other specific platforms; (c) an analysis of institutional affiliations, research groups, résumés on Lattes platform, and interviews available online. At the end, this study presents political-academic considerations about studies conducted in Brazil in articulations with Latin American Cultural Studies

    Star Formation Histories of the LEGUS dwarf galaxies. II. Spatially resolved star formation history of the Magellanic irregular NGC 4449

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    We present a detailed study of the Magellanic irregular galaxy NGC 4449 based on both archival and new photometric data from the Legacy Extragalactic UV Survey, obtained with the Hubble Space Telescope Advanced Camera for Surveys and Wide Field Camera 3. Thanks to its proximity (D=3.82±0.27D=3.82\pm 0.27 Mpc) we reach stars 3 magnitudes fainter than the tip of the red giant branch in the F814W filter. The recovered star formation history spans the whole Hubble time, but due to the age-metallicity degeneracy of the red giant branch stars, it is robust only over the lookback time reached by our photometry, i.e. 3\sim 3 Gyr. The most recent peak of star formation is around 10 Myr ago. The average surface density star formation rate over the whole galaxy lifetime is 0.010.01 M_{\odot} yr1^{-1} kpc2^{-2}. From our study it emerges that NGC 4449 has experienced a fairly continuous star formation regime in the last 1 Gyr with peaks and dips whose star formation rates differ only by a factor of a few. The very complex and disturbed morphology of NGC 4449 makes it an interesting galaxy for studies of the relationship between interactions and starbursts, and our detailed and spatially resolved analysis of its star formation history does indeed provide some hints on the connection between these two phenomena in this peculiar dwarf galaxy.Comment: 16 pages, 25 figures. Accepted for publication in the Astrophysical Journa

    Why cultural studies?

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    Por Que Estudos Culturais? Argumenta-se, neste texto, que a vitalidade dos Estudos Culturais está na abertura e receptividade para promover enlaces conceituais e teóricos variados. De modo a adensar a discussão sobre o frutífero encontro entre Estudos Culturais e Educação, no presente artigo promove-se um rastreamento de pesquisas sobre natureza e, também, daquelas dedicadas às temáticas indígenas e afro-brasileiras de modo a indicar enlaces teóricos, caminhos investigativos e pontos de atenção promovidos por pesquisadores identificados com este campo articulatório. Observa-se que, como parte de um projeto ético-político mais amplo, estes estudos questionam essencialismos, fundamentalismos, eurocentrismos, racismos e acenam para possíveis formas de resistência político-acadêmica.Why Cultural Studies? In this text it is argued that the vitality of Cultural Studies is in its openness and receptivity to promote varied conceptual and theoretical articulations. In order to deepen the analysis on the productive encounter between Cultural Studies and education, this article makes a survey of researchs on nature and, also, of those themes dedicated to indigenous and afro-Brazilians. It is done in order to indicate theoretical articulations, investigative paths and points of attention promoted by researchers identified with this articulatory field. As part of a broader ethicalpolitical project, it is observed that these studies question essentialisms, fundamentalisms, eurocentris

    Modulation of gonadotrophin induced steroidogenic enzymes in granulosa cells by d-chiroinositol

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    d-chiroinositol (DCI) is a inositolphosphoglycan (IPG) involved in several cellular functions that control the glucose metabolism. DCI functions as second messenger in the insulin signaling pathway and it is considered an insulin sensitizer since deficiency in tissue availability of DCI were shown to cause insulin resistance (IR). Polycystic ovary syndrome (PCOS) is a pathological condition that is often accompanied with insulin resistance. DCI can positively affects several aspect of PCOS etiology decreasing the total and free testosterone, lowering blood pressure, improving the glucose metabolism and increasing the ovulation frequency. The purpose of this study was to evaluate the effects of DCI and insulin combined with gonadotrophins namely follicle-stimulating hormone (FSH) and luteinizing hormone (LH) on key steroidogenic enzymes genes regulation, cytochrome P450 family 19 subfamily A member 1 (CYP19A1) and cytochrome P450 side-chain cleavage (P450scc) in primary cultures of human granulosa cells (hGCs). We also investigated whether DCI, being an insulin-sensitizer would be able to counteract the expected stimulator activity of insulin on human granulosa cells (hGCs)

    The cientificWorldJOURNAL Clinical Study A Prospective Study Evaluating IOP Changes after Switching from a Therapy with Prostaglandin Eye Drops Containing Preservatives to Nonpreserved Tafluprost in Glaucoma Patients

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    . Purpose. To compare the ocular hypotensive effect of tafluprost with prostaglandin analogues (PGAs) in glaucoma patients. Methods. 89 primary open-angle glaucoma patients treated with bimatoprost, latanoprost, or travoprost for at least 3 months complaining for ocular discomfort were switched to tafluprost. IOP was assessed at baseline and 3 months after switching the therapy by daily curve. Primary outcome was to compare the mean daily IOP of tafluprost with PGAs. Results. The mean daily IOP was 16 ± 2.1 and 16.6 ± 2.0 mm Hg at baseline and after switching to tafluprost, respectively (P &gt; 0.05). When analysis was carried out between tafluprost and each previous PGAs, the comparison between latanoprost and tafluprost and travoprost and tafluprost did not show any statistically significant difference in mean daily IOP and at each time point. The comparison between bimatoprost and tafluprost showed a statistically significant difference in mean daily IOP (P &lt; 0.05) and at each time point (P &lt; 0.05). Conclusions. After 3 months of switching tafluprost showed an overall IOP lowering effect similar to others PGAs. When each PGA was compared with tafluprost, bimatoprost showed to provide a statistically significant additional IOP lowering effect

    Western Diet-Induced Metabolic Alterations Affect Circulating Markers of Liver Function before the Development of Steatosis

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    Since nutrition might have a significant impact on liver function, we analyzed the early effect of Western-type diet on hepatic tissue and lipid and drug metabolism in Wistar-Kyoto rats (n = 8); eight rats fed with a standard diet were used as controls. Histological analysis of liver tissue was performed, and plasma biochemical parameters were measured. Plasma concentration of six bile acids was determined by ultra-liquid chromatography-tandem mass spectrometry UHPLC-MS/MS. Hepatic gene expressions of enzymes involved in drug and lipid metabolism were assessed by means of real-time reverse transcription (qRT)-PCR. Liver of rats fed with a Western diet did not show macroscopic histological alterations, but number and diameter of lipid droplets increased, as well as DGAT1, GPAT4, SCD, FASN and SREBP2 expression. Furthermore, Western diet-fed animals showed an increase in the activation of hepatic stellate cells and macrophage number in liver tissue, as well as a significant increase in AST and bilirubin levels (p < 0.01), and in the LDL:HDL cholesterol ratio (p < 0.001). Plasma chenodeoxycholic acid concentration increased significantly, whereas cholic acid decreased (p < 0.05), and cytochrome P450 genes were generally downregulated. Significant changes in hepatic lipid and drug metabolism are early induced by the Western diet, prior to steatosis development. Such changes are associated with a peculiar alteration in circulating bile acids, which could represent an early marker of non-alcoholic fatty liver disease (NAFLD) development
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