2,479 research outputs found

    Warm molecular gas temperature distribution in six local infrared bright Seyfert galaxies

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    We simultaneously analyze the spectral line energy distributions (SLEDs) of CO and H2 of six local luminous infrared (IR) Seyfert galaxies. For the CO SLEDs, we used new Herschel/SPIRE FTS data (from J=4-3 to J=13-12) and ground-based observations for the lower-J CO transitions. The H2 SLEDs were constructed using archival mid-IR Spitzer/IRS and near-IR VLT/SINFONI data for the rotational and ro-vibrational H2 transitions, respectively. In total, the SLEDs contain 26 transitions with upper level energies between 5 and 15000 K. A single, constant density, model (nH2_{H_2} ~ 104.56^{4.5-6} cm3^{-3}) with a broken power-law temperature distribution reproduces well both the CO and H2 SLEDs. The power-law indices are β1\beta_1 ~ 1-3 for warm molecular gas (20 K < T 100 K). We show that the steeper temperature distribution (higher β\beta) for hot molecular gas can be explained by shocks and photodissociation region (PDR) models, however, the exact β\beta values are not reproduced by PDR or shock models alone and a combination of both is needed. We find that the three major mergers among our targets have shallower temperature distributions for warm molecular gas than the other three spiral galaxies. This can be explained by a higher relative contribution of shock excitation, with respect to PDR excitation, for the warm molecular gas in these mergers. For only one of the mergers, IRASF 05189-2524, the shallower H2 temperature distribution differs from that of the spiral galaxies. The presence of a bright active galactic nucleus in this source might explain the warmer molecular gas observed.Comment: A&A in press; 15 pages, 7 figures. Fixed several typo

    Speech therapy assessment of language skills in a teenager with foetal alcohol syndrome: a case study

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    The present case study presents the speech therapy evaluation of a 17-year-old adolescent patient, adopted in an Eastern country, with borderline intellectual disability and sensory problems. After the initial evaluation, a specific lexical-syntactic language disorder was diagnosed, with comorbidity with evolutionary dyslexia and severe sensorial problems. Parallel to the diagnosis, it was postulated that the adolescent had foetal alcohol syndrome associated with prenatal alcohol exposure, both due to her clinical condition and suspicion from her adoption history. After a year of speech therapy intervention, the girl showed no improvement.El presente estudio de caso presenta la evaluación de una paciente adolescente de 17 años, adoptada en los países del Este, con discapacidad intelectual límite y problemas sensoriales. Tras la evaluación inicial se diagnosticó un trastorno del desarrollo del lenguaje de tipo fonológico-sintáctico, con comorbilidad con dislexia evolutiva e importantes problemas sensoriales. Paralelamente al diagnóstico se postuló que la adolescente sufriría síndrome de alcoholismo fetal asociado a la exposición prenatal al alcohol, tanto por su cuadro clínico como por las sospechas de su historial de adopción

    Molecular Dynamics Simulation of Polymer-Metal Bonds

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    Molecular simulation is becoming a very powerful tool for studying dynamic phenomena in materials. The simulation yields information about interaction at length and time scales unattainable by experimental measurements and unpredictable by continuum theories. This is especially meaningful when referring to bonding between a polymer and a metal substrate. A very important characteristic of polymers is that their physical properties do not rely on the detailed chemical structure of the molecular chains but only on their flexibility, and accordingly they will be able to adopt different conformations. In this paper, a molecular simulation of the bonding between vinyl ester polymer and steel is presented. Four different polymers with increasing chain lengths have been studied. Atomic co-ordinates are adjusted in order to reduce the molecular energy. Conformational changes in the macromolecules have been followed to obtain the polymer pair correlation function. Radius of gyration and end-to-end distance distributions of the individual chains have been used as a quantitative measurement of their flexibility. There exists a correlation between flexibility of the molecular chains and the energy of adhesion between the polymer and the metal substrate. Close contacts between the two materials are established at certain points but every atom up to a certain distance from the interface contributes to the total value of the adhesion energy of the system

    Characterization of corneal structure in keratoconus

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    Producción CientíficaThe increasing volume of patients interested in refractive surgery and the new treatment options available for keratoconus have generated a higher interest in achieving a better characterization of this pathology. The ophthalmic devices for corneal analysis and diagnosis have experienced a rapid development during the past decade with the implementation of technologies such as the Placido-disk corneal topography and the introduction of others such as scanning-slit topography, Scheimpflug photography, and optical coherence tomography, which are able to accurately describe not only the geometry of the anterior corneal surface but also that of the posterior surface, as well as pachymetry and corneal volume. Specifically, anterior and posterior corneal elevation, corneal power, pachymetry maps, and corneal coma-like aberrometry data provide sufficient information for an accurate characterization of the cornea to avoid misleading diagnoses of patients and provide appropriate counseling of refractive surgery candidates

    Can we measure mesopic pupil size with the cobalt blue light slit-lamp biomicroscopy method?

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    Producción CientíficaThe aim of this work is to assess a previously described slit-lamp biomicroscopy-based method (SLBM) for measuring pupil diameter and compare it to Colvard infrared pupillometry (CIP). METHODS: Two examiners performed three repeated measurements with each instrument in 40 healthy eyes. We determined the agreement of SLBM and CIP, intraobserver and interobserver repeatabilities, and interobserver concordance (kappa) and SLBM ability for detecting pupil sizes over 6.0 mm. RESULTS: The mean (±standard deviation [SD]) pupil diameter was 5.81 ± 0.70 mm with SLBM and 6.26 ± 0.68 mm with CIP (p = 0.01) averaging both examiner's results. Mean differences between the SLBM and CIP were -0.60 mm and -0.30 mm for each examiner using the average of the three readings (p = 0.02), and they were very similar using the first reading. Intraobserver reproducibility: the width of the 95% LoA ranged from 1.79 to 2.30 mm. The ICCs were 0.97 and 0.92 for SLBM, and 0.96 and 0.90 for CIP. Interobserver reproducibility: the width of the LoA ranged from 1.82 to 2.09 mm. Kappa statistics were 0.39 and 0.49 for the first and mean SLBM readings, respectively, and 0.45 for both the first and mean CIP readings. Sensitivity and specificity of SLBM for detection of pupils larger than 6 mm ranged from 55.56% to 73.68% and from 76.19% to 95.45%, respectively. The best trade-off between sensitivity and specificity ranged from 5.4 mm to 6.2 mm. CONCLUSIONS: Although the SLBM is quite repeatable, it underestimates mesopic pupil size and shows a too wide range of agreement with CIP. SLBM shows low sensitivity in detecting pupils larger than 6 mm, which may be misleading when planning anterior segment surgery. Previous grading-consensus training strategies may increase interrater reproducibility, and compensation for the systematic underestimation could improve accuracy of the SLBM

    A Deeper Microscopic Study of the Interaction between Gum Rosin Derivatives and a Mater-Bi Type Bioplastic

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    [EN] The interaction between gum rosin and gum rosin derivatives with Mater-Bi type bioplastic, a biodegradable and compostable commercial bioplastic, were studied. Gum rosin and two pentaerythritol esters of gum rosin (Lurefor 125 resin and Unik Tack P100 resin) were assessed as sustainable compatibilizers for the components of Mater-Bi® NF 866 polymeric matrix. To study the influence of each additive in the polymeric matrix, each gum rosin-based additive was compounded in 15 wt % by melt-extrusion and further injection molding process. Then, the mechanical properties were assessed, and the tensile properties and impact resistance were determined. Microscopic analyses were carried out by field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM) and atomic force microscopy with nanomechanical assessment (AFM-QNM). The oxygen barrier and wettability properties were also assayed. The study revealed that the commercial thermoplastic starch is mainly composed of three phases: A polybutylene adipate-co-terephthalate (PBAT) phase, an amorphous phase of thermoplastic starch (TPSa), and a semi-crystalline phase of thermoplastic starch (TPSc). The poor miscibility among the components of the Mater-Bi type bioplastic was confirmed. Finally, the formulations with the gum rosin and its derivatives showed an improvement of the miscibility and the solubility of the components depending on the additive usedThis research was funded by Spanish Ministry of Economy and Competitiveness (MINECO), project: PROMADEPCOL (MAT2017-84909-C2-2-R) and M.P.A. s contract: Juan de la Cierva-Incorporación (FJCI-2017-33536).Aldas-Carrasco, MF.; Rayón, E.; López-Martínez, J.; Arrieta, MP. (2020). A Deeper Microscopic Study of the Interaction between Gum Rosin Derivatives and a Mater-Bi Type Bioplastic. Polymers. 12(1):1-17. https://doi.org/10.3390/polym12010226S117121Keshavarz, T., & Roy, I. (2010). Polyhydroxyalkanoates: bioplastics with a green agenda. Current Opinion in Microbiology, 13(3), 321-326. doi:10.1016/j.mib.2010.02.006Aldas, M., Paladines, A., Valle, V., Pazmiño, M., & Quiroz, F. (2018). Effect of the Prodegradant-Additive Plastics Incorporated on the Polyethylene Recycling. International Journal of Polymer Science, 2018, 1-10. doi:10.1155/2018/2474176Arrieta, M. P., Peponi, L., López, D., & Fernández-García, M. (2018). Recovery of yerba mate (Ilex paraguariensis) residue for the development of PLA-based bionanocomposite films. Industrial Crops and Products, 111, 317-328. doi:10.1016/j.indcrop.2017.10.042Akrami, M., Ghasemi, I., Azizi, H., Karrabi, M., & Seyedabadi, M. (2016). A new approach in compatibilization of the poly(lactic acid)/thermoplastic starch (PLA/TPS) blends. Carbohydrate Polymers, 144, 254-262. doi:10.1016/j.carbpol.2016.02.035Elfehri Borchani, K., Carrot, C., & Jaziri, M. (2015). Biocomposites of Alfa fibers dispersed in the Mater-Bi® type bioplastic: Morphology, mechanical and thermal properties. Composites Part A: Applied Science and Manufacturing, 78, 371-379. doi:10.1016/j.compositesa.2015.08.023Sessini, V., Arrieta, M. P., Fernández-Torres, A., & Peponi, L. (2018). Humidity-activated shape memory effect on plasticized starch-based biomaterials. Carbohydrate Polymers, 179, 93-99. doi:10.1016/j.carbpol.2017.09.070Arrieta, M., Samper, M., Aldas, M., & López, J. (2017). On the Use of PLA-PHB Blends for Sustainable Food Packaging Applications. Materials, 10(9), 1008. doi:10.3390/ma10091008Aldas, M., Ferri, J. M., Lopez‐Martinez, J., Samper, M. D., & Arrieta, M. P. (2019). Effect of pine resin derivatives on the structural, thermal, and mechanical properties of Mater‐Bi type bioplastic. Journal of Applied Polymer Science, 137(4), 48236. doi:10.1002/app.48236Sessini, V., Navarro-Baena, I., Arrieta, M. P., Dominici, F., López, D., Torre, L., … Peponi, L. (2018). Effect of the addition of polyester-grafted-cellulose nanocrystals on the shape memory properties of biodegradable PLA/PCL nanocomposites. Polymer Degradation and Stability, 152, 126-138. doi:10.1016/j.polymdegradstab.2018.04.012Sessini, V., Arrieta, M. P., Raquez, J.-M., Dubois, P., Kenny, J. M., & Peponi, L. (2019). Thermal and composting degradation of EVA/Thermoplastic starch blends and their nanocomposites. Polymer Degradation and Stability, 159, 184-198. doi:10.1016/j.polymdegradstab.2018.11.025Kaseem, M., Hamad, K., & Deri, F. (2012). Thermoplastic starch blends: A review of recent works. Polymer Science Series A, 54(2), 165-176. doi:10.1134/s0965545x1202006xOlivato, J. B., Nobrega, M. M., Müller, C. M. O., Shirai, M. A., Yamashita, F., & Grossmann, M. V. E. (2013). Mixture design applied for the study of the tartaric acid effect on starch/polyester films. Carbohydrate Polymers, 92(2), 1705-1710. doi:10.1016/j.carbpol.2012.11.024Yoshida, Y., & Uemura, T. (1994). Properties and Applications of «Mater-Bi». Biodegradable Plastics and Polymers, 443-450. doi:10.1016/b978-0-444-81708-2.50049-xNainggolan, H., Gea, S., Bilotti, E., Peijs, T., & Hutagalung, S. D. (2013). Mechanical and thermal properties of bacterial-cellulose-fibre-reinforced Mater-Bi® bionanocomposite. Beilstein Journal of Nanotechnology, 4, 325-329. doi:10.3762/bjnano.4.37Ferri, J. M., Garcia-Garcia, D., Sánchez-Nacher, L., Fenollar, O., & Balart, R. (2016). The effect of maleinized linseed oil (MLO) on mechanical performance of poly(lactic acid)-thermoplastic starch (PLA-TPS) blends. Carbohydrate Polymers, 147, 60-68. doi:10.1016/j.carbpol.2016.03.082Morreale, M., Scaffaro, R., Maio, A., & La Mantia, F. P. (2008). Effect of adding wood flour to the physical properties of a biodegradable polymer. Composites Part A: Applied Science and Manufacturing, 39(3), 503-513. doi:10.1016/j.compositesa.2007.12.002Nayak, S. K. (2010). Biodegradable PBAT/Starch Nanocomposites. Polymer-Plastics Technology and Engineering, 49(14), 1406-1418. doi:10.1080/03602559.2010.496397González Seligra, P., Eloy Moura, L., Famá, L., Druzian, J. I., & Goyanes, S. (2016). Influence of incorporation of starch nanoparticles in PBAT/TPS composite films. Polymer International, 65(8), 938-945. doi:10.1002/pi.5127Arrieta, M. P., Samper, M. D., Jiménez-López, M., Aldas, M., & López, J. (2017). Combined effect of linseed oil and gum rosin as natural additives for PVC. Industrial Crops and Products, 99, 196-204. doi:10.1016/j.indcrop.2017.02.009Gutierrez, J., & Tercjak, A. (2014). Natural gum rosin thin films nanopatterned by poly(styrene)-block-poly(4-vinylpiridine) block copolymer. RSC Advances, 4(60), 32024. doi:10.1039/c4ra04296dWilbon, P. A., Chu, F., & Tang, C. (2012). Progress in Renewable Polymers from Natural Terpenes, Terpenoids, and Rosin. Macromolecular Rapid Communications, 34(1), 8-37. doi:10.1002/marc.201200513Rodríguez-García, A., Martín, J. A., López, R., Mutke, S., Pinillos, F., & Gil, L. (2015). Influence of climate variables on resin yield and secretory structures in tapped Pinus pinaster Ait. in central Spain. Agricultural and Forest Meteorology, 202, 83-93. doi:10.1016/j.agrformet.2014.11.023Davis, G., & Song, J. H. (2006). Biodegradable packaging based on raw materials from crops and their impact on waste management. Industrial Crops and Products, 23(2), 147-161. doi:10.1016/j.indcrop.2005.05.004Yadav, B. K., Gidwani, B., & Vyas, A. (2015). Rosin: Recent advances and potential applications in novel drug delivery system. Journal of Bioactive and Compatible Polymers, 31(2), 111-126. doi:10.1177/0883911515601867Butt, H.-J., Cappella, B., & Kappl, M. (2005). Force measurements with the atomic force microscope: Technique, interpretation and applications. Surface Science Reports, 59(1-6), 1-152. doi:10.1016/j.surfrep.2005.08.003J. Roa, J., Rayon, E., Morales, M., & Segarra, M. (2012). Contact Mechanics at Nanometric Scale Using Nanoindentation Technique for Brittle and Ductile Materials. Recent Patents on Engineering, 6(2), 116-126. doi:10.2174/187221212801227130Hernández‐Fernández, J., Rayón, E., López, J., & Arrieta, M. P. (2019). Enhancing the Thermal Stability of Polypropylene by Blending with Low Amounts of Natural Antioxidants. Macromolecular Materials and Engineering, 304(11), 1900379. doi:10.1002/mame.201900379Taguet, A., Huneault, M. A., & Favis, B. D. (2009). Interface/morphology relationships in polymer blends with thermoplastic starch. Polymer, 50(24), 5733-5743. doi:10.1016/j.polymer.2009.09.055Zhang, S., He, Y., Lin, Z., Li, J., & Jiang, G. (2019). Effects of tartaric acid contents on phase homogeneity, morphology and properties of poly (butyleneadipate-co-terephthalate)/thermoplastic starch bio-composities. Polymer Testing, 76, 385-395. doi:10.1016/j.polymertesting.2019.04.005Mohammadi Nafchi, A., Moradpour, M., Saeidi, M., & Alias, A. K. (2013). Thermoplastic starches: Properties, challenges, and prospects. Starch - Stärke, 65(1-2), 61-72. doi:10.1002/star.201200201Van Soest, J. J. G., De Wit, D., & Vliegenthart, J. F. G. (1996). Mechanical properties of thermoplastic waxy maize starch. Journal of Applied Polymer Science, 61(11), 1927-1937. doi:10.1002/(sici)1097-4628(19960912)61:113.0.co;2-lZhang, Y., Rempel, C., & Liu, Q. (2014). Thermoplastic Starch Processing and Characteristics—A Review. Critical Reviews in Food Science and Nutrition, 54(10), 1353-1370. doi:10.1080/10408398.2011.636156Yu, J., Gao, J., & Lin, T. (1996). Biodegradable thermoplastic starch. Journal of Applied Polymer Science, 62(9), 1491-1494. doi:10.1002/(sici)1097-4628(19961128)62:93.0.co;2-1Zullo, R., & Iannace, S. (2009). The effects of different starch sources and plasticizers on film blowing of thermoplastic starch: Correlation among process, elongational properties and macromolecular structure. Carbohydrate Polymers, 77(2), 376-383. doi:10.1016/j.carbpol.2009.01.007Sousa, F. M., Costa, A. R. M., Reul, L. T. A., Cavalcanti, F. B., Carvalho, L. H., Almeida, T. G., & Canedo, E. L. (2018). Rheological and thermal characterization of PCL/PBAT blends. Polymer Bulletin, 76(3), 1573-1593. doi:10.1007/s00289-018-2428-5Mittal, V., Akhtar, T., Luckachan, G., & Matsko, N. (2014). PLA, TPS and PCL binary and ternary blends: structural characterization and time-dependent morphological changes. Colloid and Polymer Science, 293(2), 573-585. doi:10.1007/s00396-014-3458-7Arrieta, M. P., López, J., Hernández, A., & Rayón, E. (2014). Ternary PLA–PHB–Limonene blends intended for biodegradable food packaging applications. European Polymer Journal, 50, 255-270. doi:10.1016/j.eurpolymj.2013.11.009Burgos, N., Martino, V. P., & Jiménez, A. (2013). Characterization and ageing study of poly(lactic acid) films plasticized with oligomeric lactic acid. Polymer Degradation and Stability, 98(2), 651-658. doi:10.1016/j.polymdegradstab.2012.11.009Armentano, I., Fortunati, E., Burgos, N., Dominici, F., Luzi, F., Fiori, S., … Kenny, J. M. (2015). Processing and characterization of plasticized PLA/PHB blends for biodegradable multiphase systems. Express Polymer Letters, 9(7), 583-596. doi:10.3144/expresspolymlett.2015.55Arrieta, M. P., Peltzer, M. A., López, J., Garrigós, M. del C., Valente, A. J. M., & Jiménez, A. (2014). Functional properties of sodium and calcium caseinate antimicrobial active films containing carvacrol. Journal of Food Engineering, 121, 94-101. doi:10.1016/j.jfoodeng.2013.08.015Hambleton, A., Fabra, M.-J., Debeaufort, F., Dury-Brun, C., & Voilley, A. (2009). Interface and aroma barrier properties of iota-carrageenan emulsion–based films used for encapsulation of active food compounds. Journal of Food Engineering, 93(1), 80-88. doi:10.1016/j.jfoodeng.2009.01.00

    Interface Scaling in the Contact Process

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    Scaling properties of an interface representation of the critical contact process are studied in dimensions 1 - 3. Simulations confirm the scaling relation beta_W = 1 - theta between the interface-width growth exponent beta_W and the exponent theta governing the decay of the order parameter. A scaling property of the height distribution, which serves as the basis for this relation, is also verified. The height-height correlation function shows clear signs of anomalous scaling, in accord with Lopez' analysis [Phys. Rev. Lett. 83, 4594 (1999)], but no evidence of multiscaling.Comment: 10 pages, 9 figure

    Autoantibodies against perilipin 1 as a cause of acquired generalized lipodystrophy

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    Acquired generalized lipodystrophy (AGL) is a rare condition characterized by an altered distribution of adipose tissue and predisposition to develop hepatic steatosis and fibrosis, diabetes, and hypertriglyceridemia. Diagnosis of AGL is based on the observation of generalized fat loss, autoimmunity and lack of family history of lipodystrophy. The pathogenic mechanism of fat destruction remains unknown but evidences suggest an autoimmune origin. Anti-adipocyte antibodies have been previously reported in patients with AGL, although their involvement in the pathogenesis has been poorly studied and the autoantibody target/s remain/s to be identified. Using a combination of immunochemical and cellular studies, we investigated the presence of anti-adipocyte autoantibodies in patients with AGL, acquired partial lipodystrophy, localized lipoatrophy due to intradermic insulin injections or systemic lupus erythematosus. Moreover, the impact of anti-adipocyte autoantibodies from AGL patients was assessed in cultured mouse preadipocytes. Following this approach, we identified anti-perilipin 1 IgG autoantibodies in the serum of patients with autoimmune variety-AGL, but in no other lipodystrophies tested. These autoantibodies altered the ability of perilipin 1 to regulate lipolysis in cultured preadipocytes causing abnormal, significantly elevated basal lipolysis. Our data provide strong support for the conclusion that perilipin 1 autoantibodies are a cause of generalized lipodystrophy in these patientsFC, ML-T, AL-L, and SG were supported by grants PI15- 00255 from Instituto de Salud Carlos III (ISCIII, Ministerio de Economía y Competitividad) and Fondos FEDER, Complemento II-CM network (B2017/BMD3673), Acciones Cooperativas y Complementarias Intramurales (ACCI) from CIBERER (ISCIII), and Fundación SENEFRO. MdMwas supported by Roche Farma SA and Foundation Domingo Martínez. VA was financed by Consejería de Educación, Juventud y Deporte of Comunidad de Madrid and by Fondo Social Europeo (Programa Operativo de Empleo Juvenil, and Iniciativa de Empleo Juvenil (YEI), (PEJ15/BIO/AI/0045). DA-V was supported by the intramural research program of the Xunta de Galicia (Programa de Consolidación e Estructuración de Unidades de Investigación Competitivas, grant ED341b 2017/19), by the Instituto de Salud Carlos III (grant number: PI08-1449) and the European Regional Development Fund, FEDER and by the Asociación Española de Familiares y Afectados de Lipodistrofias (AELIP

    Student Reciprocal Peer Teaching as a Method for Active Learning: An Experience in an Electrotechnical Laboratory

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    Active learning is one of the most efficient mechanisms for learning, according to the psychology of learning. When students act as teachers for other students, the communication is more fluent and knowledge is transferred easier than in a traditional classroom. This teaching method is referred to in the literature as reciprocal peer teaching. In this study, the method is applied to laboratory sessions of a higher education institution course, and the students who act as teachers are referred to as ‘‘laboratory monitors.’’ A particular way to select the monitors and its impact in the final marks is proposed. A total of 181 students participated in the experiment, experiences with laboratory monitors are discussed, and methods for motivating and training laboratory monitors and regular students are proposed. The types of laboratory sessions that can be led by classmates are discussed. This work is related to the changes in teaching methods in the Spanish higher education system, prompted by the Bologna Process for the construction of the European Higher Education Are
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