256 research outputs found

    Fragrance materials (FMs) affect the larval development of the copepod Acartia tonsa: An emerging issue for marine ecosystems

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    Fragrance materials (FMs) are used in a variety of detergents and cosmetics, including household and personal care products. Despite their widespread use and the growing evidence of their occurrence in surface waters worldwide, very little is known about their toxicity towards marine species, including a key component of the marine food webs such as copepods. Thus, we investigated the toxicity of six of the more long-lasting and stable commercial fragrances, including Amyl Salicylate (AMY), Oranger Crystals (ORA), Hexyl Salicylate (HEX), Ambrofix (AMB), Peonile (PEO), and Benzyl Salicylate (BZS), to assess their ability to impair the larval development of the calanoid copepod Acartia tonsa. FMs inhibited the development of A. tonsa significantly at concentrations by far lower than the effect-concentrations reported in the literature for aquatic species. The more toxic FMs were HEX (EC50 = 57 ng L−1), AMY (EC50 = 131 ng L−1) and ORA (EC50 = 766 ng L−1), while the other three compounds exerted toxic effects at concentrations higher than 1000 ng L−1 (LOEC at 1000 ng L−1 for PEO and BZS, and at 10,000 ng L−1 for AMB). Early life-stage mortality was unaffected by FMs at all the tested concentrations. A comparison with water concentrations of FMs reported in the literature confirmed that FMs, especially HEX and AMY, may act as contaminants of potential concern in many aquatic habitats, including urban areas and remote and polar environments

    The XMM Cluster Outskirts Project (X-COP): thermodynamic properties of the intracluster medium out to R 200 in Abell 2319

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    Aims. We present the joint analysis of the X-ray and Sunyaev Zel’dovich(SZ) signals in Abell 2319, the galaxy cluster with the highest signal-to-noise ratio in SZ Planck maps and that has been surveyed within our XMM-Newton Cluster Outskirts Project (X-COP), a very large program which aims to grasp the physical condition in 12 local (z < 0.1) and massive (M200 > 3 × 1014 M⊙) galaxy clusters out to R200 and beyond. Methods. We recover the profiles of the thermodynamic properties by the geometrical deprojection of the X-ray surface brightness, of the SZ Comptonization parameter, and accurate and robust spectroscopic measurements of the gas temperature out to 3.2 Mpc (1.6 R200 ), 4 Mpc (2 R200 ), and 1.6 Mpc (0.8 R200 ), respectively. We resolve the clumpiness of the gas density to be below 20% over the entire observed volume. We also demonstrate that most of this clumpiness originates from the ongoing merger and can be associated with large-scale inhomogeneities (the “residual” clumpiness). We estimate the total mass through the hydrostatic equilibrium equation. This analysis is done both in azimuthally averaged radial bins and in eight independent angular sectors, enabling us to study in detail the azimuthal variance of the recovered properties. Results. Given the exquisite quality of the X-ray and SZ datasets, their radial extension, and their complementarity, we constrain at R200 the total hydrostatic mass, modelled with a Navarro–Frenk–White profile at very high precision (M200 = 10.7 ± 0.5stat. ± 0.9syst. × 1014 M⊙). We identify the ongoing merger and how it is affecting differently the gas properties in the resolved azimuthal sectors. We have several indications that the merger has injected a high level of non-thermal pressure in this system: the clumping free density profile is above the average profile obtained by stacking Rosat/PSPC observations; the gas mass fraction recovered using our hydrostatic mass profile exceeds the expected cosmic gas fraction beyond R500; the pressure profile is flatter than the fit obtained by the Planck Collaboration; the entropy profile is flatter than the mean profile predicted from non-radiative simulations; the analysis in azimuthal sectors has revealed that these deviations occur in a preferred region of the cluster. All these tensions are resolved by requiring a relative support of about 40% from non-thermal to the total pressure at R200

    The role of preclinical models in creatine transporter deficiency: Neurobiological mechanisms, biomarkers and therapeutic development

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    Creatine (Cr) Transporter Deficiency (CTD) is an X-linked metabolic disorder, mostly caused by missense mutations in the SLC6A8 gene and presenting with intellectual disability, autistic behavior, and epilepsy. There is no effective treatment for CTD and patients need lifelong assistance. Thus, the research of novel intervention strategies is a major scientific challenge. Animal models are an excellent tool to dissect the disease pathogenetic mechanisms and drive the preclinical development of therapeutics. This review illustrates the current knowledge about Cr metabolism and CTD clinical aspects, with a focus on mainstay diagnostic and therapeutic options. Then, we discuss the rodent models of CTD characterized in the last decade, comparing the phenotypes expressed within clinically relevant domains and the timeline of symptom development. This analysis highlights that animals with the ubiquitous deletion/mutation of SLC6A8 genes well recapitulate the early onset and the complex pathological phenotype of the human condition. Thus, they should represent the preferred model for preclinical efficacy studies. On the other hand, brain-and cell-specific conditional mutants are ideal for understanding the basis of CTD at a cellular and molecular level. Finally, we explain how CTD models might provide novel insight about the pathogenesis of other disorders, including cancer

    Vertebral artery dissection in term pregnancy after cervical spine manipulation: a case report and review the literature

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    Background: Vertebral artery dissection is an uncommon, but potentially fatal, vascular event. This case aimed to describe the pathogenesis and clinical presentation of vertebral artery dissection in a term pregnant patient. Moreover, we focused on the differential diagnosis, reviewing the available evidence. Case presentation: A 39-year-old Caucasian woman presented at 38 + 4 weeks of gestation with a short-term history of vertigo, nausea, and vomiting. Symptoms appeared a few days after cervical spine manipulation by an osteopathic specialist. Urgent magnetic resonance imaging of the head was obtained and revealed an ischemic lesion of the right posterolateral portion of the brain bulb. A subsequent computed tomography angiographic scan of the head and neck showed a right vertebral artery dissection. Based on the correlation of the neurological manifestations and imaging findings, a diagnosis of vertebral artery dissection was established. The patient started low-dose acetylsalicylic acid and prophylactic enoxaparin following an urgent cesarean section. Conclusion: Vertebral artery dissection is a rare but potential cause of neurologic impairments in pregnancy and during the postpartum period. It should be considered in the differential diagnosis for women who present with headache and/or vertigo. Women with a history of migraines, hypertension, or autoimmune disorders in pregnancy are at higher risk, as well as following cervical spine manipulations. Prompt diagnosis and management of vertebral artery dissection are essential to ensure favorable outcomes

    High-resolution global grids of revised Priestley–Taylor and Hargreaves–Samani coefficients for assessing ASCE-standardized reference crop evapotranspiration and solar radiation

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    Abstract. The objective of the study is to provide global grids (0.5°) of revised annual coefficients for the Priestley–Taylor (P-T) and Hargreaves–Samani (H-S) evapotranspiration methods after calibration based on the ASCE (American Society of Civil Engineers)-standardized Penman–Monteith method (the ASCE method includes two reference crops: short-clipped grass and tall alfalfa). The analysis also includes the development of a global grid of revised annual coefficients for solar radiation (Rs) estimations using the respective Rs formula of H-S. The analysis was based on global gridded climatic data of the period 1950–2000. The method for deriving annual coefficients of the P-T and H-S methods was based on partial weighted averages (PWAs) of their mean monthly values. This method estimates the annual values considering the amplitude of the parameter under investigation (ETo and Rs) giving more weight to the monthly coefficients of the months with higher ETo values (or Rs values for the case of the H-S radiation formula). The method also eliminates the effect of unreasonably high or low monthly coefficients that may occur during periods where ETo and Rs fall below a specific threshold. The new coefficients were validated based on data from 140 stations located in various climatic zones of the USA and Australia with expanded observations up to 2016. The validation procedure for ETo estimations of the short reference crop showed that the P-T and H-S methods with the new revised coefficients outperformed the standard methods reducing the estimated root mean square error (RMSE) in ETo values by 40 and 25 %, respectively. The estimations of Rs using the H-S formula with revised coefficients reduced the RMSE by 28 % in comparison to the standard H-S formula. Finally, a raster database was built consisting of (a) global maps for the mean monthly ETo values estimated by ASCE-standardized method for both reference crops, (b) global maps for the revised annual coefficients of the P-T and H-S evapotranspiration methods for both reference crops and a global map for the revised annual coefficient of the H-S radiation formula and (c) global maps that indicate the optimum locations for using the standard P-T and H-S methods and their possible annual errors based on reference values. The database can support estimations of ETo and solar radiation for locations where climatic data are limited and it can support studies which require such estimations on larger scales (e.g. country, continent, world). The datasets produced in this study are archived in the PANGAEA database (https://doi.org/10.1594/PANGAEA.868808) and in the ESRN database (http://www.esrn-database.org or http://esrn-database.weebly.com)

    Práticas de letramento para alunos da Educação de Jovens e Adultos Interventiva

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    Trabalho de Conclusão de Curso (especialização)—Universidade de Brasília, Ministério da Educação, Coordenação de Formação Continuada de Professores, Secretaria de Estado de Educação do Distrito Federal, Especialização em Letramento e Práticas Interdisciplinares nos Anos Finais, 2015.O objetivo do presente estudo é identificar e analisar as práticas de letramento para alunos da Educação de Jovens e Adultos Interventiva em uma escola pública do Distrito Federal. A EJA interventiva é um programa da Secretaria de Estado de Educação que tem como objetivo o atendimento dos jovens e adultos com deficiência intelectual. Para tanto, realizou-se uma pesquisa de campo, com elementos qualitativos com seis alunos com idades entre 17 e 37 anos. As técnicas utilizadas para a realização desse trabalho compreenderam a observação participante e entrevistas. Evidenciou-se por meio das observações e entrevistas, a importância do processo de letramento para a vida escolar e social desses alunos. Para analisar os dados obtidos foi utilizada a técnica de análise de conteúdo, onde foram criadas categorias. Os resultaram mostraram que o letramento dos alunos da EJA Interventiva colabora para uma vida social mais ativa e independente. Porém, algumas práticas realizadas mostram várias fragilidades deste processo, que necessita de adequações e reflexões que extrapolam a sala de aula, buscando por meio da escolarização, a inclusão desse aluno no contexto social em que vivemos e de sua emancipação

    Ultrafast optical control of nonlinear dielectric nanoantennas

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    Efficient ultrafast reconfiguration of the second-harmonic generation of AlGaAs nonlinear nanoantennas operating at 1550 nm telecom wavelength, is achieved by ultrafast interband photoexcitation with femtosecond visible pulses. The combination of broadband transient transmittivity, time-revolved second harmonic generation, and nonlinear optics nanoscale modeling, allows to track the ultrafast modulation of the second harmonic signal, into the nanoscale charge carrier dynamics at the base of a giant permittivity change at the semiconducting band edg

    The X-ray invisible Universe. A look into the halos undetected by eROSITA

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    The paper presents the analysis of GAMA spectroscopic groups and clusters detected and undetected in the SRG/eROSITA X-ray map of the eFEDS (eROSITA Final Equatorial Depth Survey) area, in the halo mass range 10135x101410^{13}-5x10^{14} MM_{\odot} and at z<0.2z < 0.2. We compare the X-ray surface brightness profiles of the eROSITA detected groups with the mean stacked profile of the undetected low-mass halos. Overall, we find that the undetected groups exhibit less concentrated X-ray surface brightness, dark matter, and galaxy distributions with respect to the X-ray detected halos. Consistently with the low mass concentration, the magnitude gap indicates that these are younger systems. The later assembly time is confirmed by the bluer average color of the BCG and of the galaxy population with respect to the detected systems. They reside with a higher probability in filaments while X-ray detected low-mass halos favor the nodes of the Cosmic Web. Because of the suppressed X-ray central emission, the undetected systems tend to be X-ray under-luminous at fixed halo mass, and to lie below the LXMhaloL_X-M_{halo} relation. Interestingly, the X-ray detected systems inhabiting the nodes scatter the less around the relation, while those in filaments tend to lie below it. We do not observe any strong relation between the properties of detected and undetected systems with the AGN activity. The fraction of optically selected AGN in the galaxy population is consistent in the two samples. More interestingly, the probability that the BCG hosts a radio AGN is lower in the undetected groups. We, thus, argue that the observed differences between X-ray detected and undetected groups are ascribable to the Cosmic Web, and its role in the halo assembly bias. Our results suggest that the X-ray selection is biased to favor the most concentrated and old systems located in the nodes of the Cosmic Web.Comment: 15 pages, 13 figures, Submitted to MNRA
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