461 research outputs found

    The effect of substituents on the syn-anti conformer ratio in naphthyl-based imidazolinium salts and their corresponding N-heterocyclic carbenes

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    Eight new N-heterocyclic carbenes (NHCs) featuring substituted naphthyl side chains were synthesized. These molecules are present in solution as a stable mixture of antiand synconformers. Through careful tuning of the substituents on position 2 and 2,7 of the naphthyl moieties, it was possible to synthesize molecules that display a strong preference for the anticonformation (up to 95:5). This will greatly facilitate their optimized use as single isomeric ligands in metal-catalysis and as organocatalysts

    Effects of COVID-19 vaccination on disease activity in patients with rheumatoid arthritis and psoriatic arthritis on targeted therapy in the COVIDSER study

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    COVID-19; Artritis psoriásica; VacunaciónCOVID 19; Artritis psoriàsica; VacunacióCOVID-19; Psoriatic arthritis; VaccinationObjective: To investigate the influence of COVID-19 vaccination on disease activity in rheumatoid arthritis (RA) and psoriatic arthritis (PsA) patients under targeted therapies. Patients and methods: 1765 vaccinated patients COVID-19, 1178 (66.7%) with RA and 587 (33.3%) with PsA from the COVID-19 registry in patients with rheumatic diseases (COVIDSER) project, were included. Demographics, disease characteristics, Disease Activity Score in 28 joints (DAS28) and targeted treatments were collected. DAS28-based flare rates and categorised disease activity distribution prevaccination and post vaccination were analysed by log-linear regression and contingency analyses, respectively. The influence of vaccination on DAS28 variation as a continuous measure was evaluated using a random coefficient model. Results: The distribution of categorised disease activity and flare rates was not significantly modified by vaccination. Log-linear regression showed no significant changes in the rate of flares in the 6-month period after vaccination compared with the same period prior to vaccination in neither patients with RA nor patients with PsA. When DAS28 variations were analysed using random coefficient models, no significant variations in disease activity were detected after vaccination for both groups of patients. However, patients with RA treated with Janus kinase inhibitors (JAK-i) (1) and interleukin-6 inhibitor (IL-6-i) experienced a worsening of disease activity (1.436±0.531, p=0.007, and 1.201±0.550, p=0.029, respectively) in comparison with those treated with tumour necrosis factor inhibitor (TNF-i). Similarly, patients with PsA treated with interleukin-12/23 inhibitor (IL-12/23-i) showed a worsening of disease activity (4.476±1.906, p=0.019) compared with those treated with TNF-i. Conclusion: COVID-19 vaccination was not associated with increased rate of flares in patients with RA and PsA. However, a potential increase in disease activity in patients with RA treated with JAK-i and IL-6-i and in patients with PsA treated with IL-12/23-i warrants further investigation

    Virtual Blocks: a serious game for spatial ability improvement on mobile devices

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    This paper presents a novel spatial instruction system for improving spatial abilities of engineering students. A 3D mobile game application called Virtual Blocks has been designed to provide a 3D virtual environment to build models with cubes that help students to perform visualization tasks to promote the development of their spatial ability during a short remedial course. A validation study with 26 freshman engineering students at La Laguna University (Spain) has concluded that the training had a measurable and positive impact on students spatial ability. In addition, the results obtained using a satisfaction questionnaire show that Virtual Blocks is considered an easy to use and stimulating application.This work has been partially supported by the (Spanish) National Program for Studies and Analysis project "Evaluation and development of competencies associated to the spatial ability in the new engineering undergraduate courses" (Ref. EA2009-0025) and the (Spanish) National Science Project "Enhancing Spatial REasoning and VIsual Cognition with advanced technological tools (ESREVIC)" (Ref TIN2010-21296-C02-02)Martín Dorta, NN.; Sanchez Berriel, I.; Bravo, M.; Hernández, J.; Saorin, JL.; Contero, M. (2014). Virtual Blocks: a serious game for spatial ability improvement on mobile devices. Multimedia Tools and Applications. 73(3):1575-1595. https://doi.org/10.1007/s11042-013-1652-0S15751595733Baartmans BG, Sorby SA (1996) Introduction to 3-D spatial visualization. Prentice Hall, Englewood CliffsClements D, Battista M (1992) Geometry and spatial reasoning. In: Grouws DA (ed) Handbook of research on mathematics teaching and learning. New York, pp 420–464Cohen J (1988) Statistical power analysis for the behavioral sciences, 2nd edn. Erlbaum, HillsdaleDe Lisi R, Cammarano DM (1996) Computer experience and gender differences in undergraduate mental rotation performance. Comput Hum Behav 12:351–361Deno JA (1995) The relationship of previous experiences to spatial visualization ability. Eng Des Graph J 59(3):5–17Feng J, Spence I, Pratt J (2007) Playing an action video game reduces gender differences in spatial cognition. Psychol Sci 18(10):850–855French JW (1951) The description of aptitude and achievement tests in terms of rotated factors. Psychometric monograph 5Guilford JP, Lacy JI (1947) Printed classification tests, A.A.F. Aviation Psychological Progress Research Report, 5. US. Government Printing Office, Washington DCHalpern DF (2000) Sex differences and cognitive abilities. Erlbaum, MahwahHöfele C (2007) Mobile 3D graphics: learning 3D graphics with the Java Micro Edition. Editorial ThomsonKajiya JT, Kay TL (1989) Rendering fur with three dimensional textures. In Proceedings of the 16th Annual Conference on Computer Graphics and interactive Techniques SIGGRAPH ’89. ACM Press, New York pp 271–280Linn MC, Petersen AC (1985) Emergence and characterization of gender differences in spatial abilities: a meta-analysis. Child Dev 56:1479–1498Martin-Dorta N, Sanchez-Berriel I, Bravo M, Hernandez J, Saorin JL, Contero M (2010) A 3D educational mobile game to enhance student’s spatial skills, ICALT, pp.6–10, 2010 10th IEEE International Conference on Advanced Learning TechnologiesMartin-Dorta N, Saorin J, Contero M (2008) Development of a fast remedial course to improve the spatial abilities of engineering students. J Eng Educ 27(4):505–514Martin-Dorta N, Saorin JL, Contero M (2011) Web-based spatial training using handheld touch screen devices. Educ Technol Soc 14(3):163–177McGee MG (1979) Human spatial abilities: psychometric studies and environmental, genetic, hormonal, and neurological influences. Psychol Bull 86:889–918Noguera JM, Segura RJ, Ogayar CJ, Joan-Arinyo R (2011) Navigating large terrains using commodity mobile devices. Comput Geosci 37:1218–1233Okagaki L, Frensch PA (1994) Effects of video game playing on measures of spatial performance: gender effects in late adolescence. J Appl Dev Psychol 15(1):33–58Pulli K, Aarnio T, Miettinen V, Roimela K, Vaarala J (2007) Mobile 3D graphics with OpenGL ES and M3G. Editorial Morgan KaufmannQuaiser-Pohl C, Geiser C, Lehmann W (2005) The relationship between computer-game preference, gender, and mental-rotation ability. Personal Individ Differ 40(3):609–619Smith IM (1964) Spatial ability- its educational and social significance. The University of London Press, LondonSorby S (2007) Developing 3D spatial skills for engineering students. Australas Assoc Eng Educ 13(1):1–11Terlecki MS, Newcombe NS (2005) How important is the digital divide? The relation of computer and videogame usage to gender differences in mental rotation ability. Sex Roles 53(5/6):433–441Terlecki MS, Newcombe NS, Little M (2008) Durable and generalized effects of spatial experience on mental rotation: gender differences in growth patterns. Appl Cogn Psychol 22:996–1013Thurstone LL (1950) Some primary abilities in visual thinking (Tech. Rep. No. 59). IL University of Chicago Psychometric Laboratory, ChicagoThurstone LL, Thurstone TG (1941) Factorial studies of intelligence. Psychometric monographs. Chicago Press, ChicagoVanderberg S, Kuse A (1978) Mental Rotation, a group test of three dimensional spatial visualization. Percept Mot Skills 47:599–604Zimmerman WS (1954) Hypotheses concerning the nature of the spatial factors. Educ Psychol Meas 14:396–40

    The correlation between halo mass and stellar mass for the most massive galaxies in the universe

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    I.Z. is supported by NSF grant AST-1612085. Funding for the Sloan Digital Sky Survey IV has been provided by the Alfred P. Sloan Foundation, the U.S. Department of Energy Office of Science, and the Participating Institutions. SDSS-IV acknowledges support and resources from the Center for High-Performance Computing at the University of Utah.We present measurements of the clustering of galaxies as a function of their stellar mass in the Baryon Oscillation Spectroscopic Survey. We compare the clustering of samples using 12 different methods for estimating stellar mass, isolating the method that has the smallest scatter at fixed halo mass. In this test, the stellar mass estimate with the smallest errors yields the highest amplitude of clustering at fixed number density. We find that the PCA stellar masses of Chen et al. clearly have the tightest correlation with halo mass. The PCA masses use the full galaxy spectrum, differentiating them from other estimates that only use optical photometric information. Using the PCA masses, we measure the large-scale bias as a function of M∗ for galaxies with log M∗ ≥ 11.4, correcting for incompleteness at the low-mass end of our measurements. Using the abundance matching ansatz to connect dark matter halo mass to stellar mass, we construct theoretical models of b (M∗) that match the same stellar mass function but have different amounts of scatter in stellar mass at fixed halo mass, σlog M∗. Using this approach, we find σlogM∗ =  0.18 -0.02 +0.01. This value includes both intrinsic scatter as well as random errors in the stellar masses. To partially remove the latter, we use repeated spectra to estimate statistical errors on the stellar masses, yielding an upper limit to the intrinsic scatter of 0.16 dex.Publisher PDFPeer reviewe

    Mathematical properties of weighted impact factors based on measures of prestige of the citing journals

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    The final publication is available at Springer via http://dx.doi.org/10.1007/s11192-015-1741-0An abstract construction for general weighted impact factors is introduced. We show that the classical weighted impact factors are particular cases of our model, but it can also be used for defining new impact measuring tools for other sources of information as repositories of datasets providing the mathematical support for a new family of altmet- rics. Our aim is to show the main mathematical properties of this class of impact measuring tools, that hold as consequences of their mathematical structure and does not depend on the definition of any given index nowadays in use. In order to show the power of our approach in a well-known setting, we apply our construction to analyze the stability of the ordering induced in a list of journals by the 2-year impact factor (IF2). We study the change of this ordering when the criterium to define it is given by the numerical value of a new weighted impact factor, in which IF2 is used for defining the weights. We prove that, if we assume that the weight associated to a citing journal increases with its IF2, then the ordering given in the list by the new weighted impact factor coincides with the order defined by the IF2. We give a quantitative bound for the errors committed. We also show two examples of weighted impact factors defined by weights associated to the prestige of the citing journal for the fields of MATHEMATICS and MEDICINE, GENERAL AND INTERNAL, checking if they satisfy the increasing behavior mentioned above.Ferrer Sapena, A.; Sánchez Pérez, EA.; González, LM.; Peset Mancebo, MF.; Aleixandre Benavent, R. (2015). Mathematical properties of weighted impact factors based on measures of prestige of the citing journals. Scientometrics. 105(3):2089-2108. https://doi.org/10.1007/s11192-015-1741-0S208921081053Ahlgren, P., & Waltman, L. (2014). The correlation between citation-based and expert-based assessments of publication channels: SNIP and SJR vs. Norwegian quality assessments. Journal of Informetrics, 8, 985–996.Aleixandre Benavent, R., Valderrama Zurián, J. C., & González Alcaide, G. (2007). Scientific journals impact factor: Limitations and alternative indicators. El Profesional de la Información, 16(1), 4–11.Altmann, K. G., & Gorman, G. E. (1998). The usefulness of impact factor in serial selection: A rank and mean analysis using ecology journals. Library Acquisitions-Practise and Theory, 22, 147–159.Arnold, D. N., & Fowler, K. K. (2011). Nefarious numbers. Notices of the American Mathematical Society, 58(3), 434–437.Beliakov, G., & James, S. (2012). Using linear programming for weights identification of generalized bonferroni means in R. In: Proceedings of MDAI 2012 modeling decisions for artificial intelligence. Lecture Notes in Computer Science, Vol. 7647, pp. 35–44.Beliakov, G., & James, S. (2011). Citation-based journal ranks: The use of fuzzy measures. Fuzzy Sets and Systems, 167, 101–119.Buela-Casal, G. (2003). Evaluating quality of articles and scientific journals. Proposal of weighted impact factor and a quality index. Psicothema, 15(1), 23–25.Dorta-Gonzalez, P., & Dorta-Gonzalez, M. I. (2013). Comparing journals from different fields of science and social science through a JCR subject categories normalized impact factor. Scientometrics, 95(2), 645–672.Dorta-Gonzalez, P., Dorta-Gonzalez, M. I., Santos-Penate, D. R., & Suarez-Vega, R. (2014). Journal topic citation potential and between-field comparisons: The topic normalized impact factor. Journal of Informetrics, 8(2), 406–418.Egghe, L., & Rousseau, R. (2002). A general frame-work for relative impact indicators. Canadian Journal of Information and Library Science, 27(1), 29–48.Gagolewski, M., & Mesiar, R. (2014). Monotone measures and universal integrals in a uniform framework for the scientific impact assessment problem. Information Sciences, 263, 166–174.Garfield, E. (2006). The history and meaning of the journal impact factor. JAMA, 295(1), 90–93.Habibzadeh, F., & Yadollahie, M. (2008). Journal weighted impact factor: A proposal. Journal of Informetrics, 2(2), 164–172.Klement, E., Mesiar, R., & Pap, E. (2010). A universal integral as common frame for Choquet and Sugeno integral. IEEE Transaction on Fuzzy System, 18, 178–187.Leydesdorff, L., & Opthof, T. (2010). Scopus’s source normalized impact per paper (SNIP) versus a journal impact factor based on fractional counting of citations. Journal of the American Society for Information Science and Technology, 61, 2365–2369.Li, Y. R., Radicchi, F., Castellano, C., & Ruiz-Castillo, J. (2013). Quantitative evaluation of alternative field normalization procedures. Journal of Informetrics, 7(3), 746–755.Moed, H. F. (2010). Measuring contextual citation impact of scientific journals. Journal of Informetrics, 4, 265–277.NISO. (2014). Alternative metrics initiative phase 1. White paper. http://www.niso.org/apps/group-public/download.php/13809/Altmetrics-project-phase1-white-paperOwlia, P., Vasei, M., Goliaei, B., & Nassiri, I. (2011). Normalized impact factor (NIF): An adjusted method for calculating the citation rate of biomedical journals. Journal of Biomedical Informatics, 44(2), 216–220.Pinski, G., & Narin, F. (1976). Citation influence for journal aggregates of scientific publications: Theory, with application to the literature of physics. Information Processing and Management, 12, 297–312.Pinto, A. C., & Andrade, J. B. (1999). Impact factor of scientific journals: What is the meaning of this parameter? Quimica Nova, 22, 448–453.Raghunathan, M. S., & Srinivas, V. (2001). Significance of impact factor with regard to mathematics journals. Current Science, 80(5), 605.Ruiz Castillo, J., & Waltman, L. (2015). Field-normalized citation impact indicators using algorithmically constructed classification systems of science. Journal of Informetrics, 9, 102–117.Saha, S., Saint, S., & Christakis, D. A. (2003). Impact factor: A valid measure of journal quality? Journal of the Medical Library Association, 91, 42–46.Torra, V., & Narukawa, Y. (2008). The h-index and the number of citations: Two fuzzy integrals. IEEE Transaction on Fuzzy System, 16, 795–797.Torres-Salinas, D., & Jimenez-Contreras, E. (2010). Introduction and comparative study of the new scientific journals citation indicators in journal citation reports and scopus. El Profesional de la Información, 19, 201–207.Waltman, L., & van Eck, N. J. (2008). Some comments on the journal weighted impact factor proposed by Habibzadeh and Yadollahie. Journal of Informetrics, 2(4), 369–372.Waltman, L., van Eck, N. J., van Leeuwen, T. N., & Visser, M. S. (2013). Some modifications to the SNIP journal impact indicator. Journal of Informetrics, 7, 272–285.Zitt, M. (2011). Behind citing-side normalization of citations: some properties of the journal impact factor. Scientometrics, 89, 329–344.Zitt, M., & Small, H. (2008). Modifying the journal impact factor by fractional citation weighting: The audience factor. Journal of the American Society for Information Science and Technology, 59, 1856–1860.Zyczkowski, K. (2010). Citation graph, weighted impact factors and performance indices. Scientometrics, 85(1), 301–315

    OCCURRENCE OF TICK-BORNE PATHOGENS IN STRAY DOGS FROM HAVANA, CUBA

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    The article presents the results of examination of stray dogs from Havana, Cuba for six ixodid tick-borne diseases. Analysis was carried  out using real-time PCR. Overall 107 dogs, 95 (89.09 %) were infected.  41 dogs (38.31 %), 66 (61.68 %), 28 (26.17 %) and 40 (37.38 %)  were found to be infected with Anaplasma platys, Ehrlichia canis,  Rickettsia spp. and Hepatozoon canis, respectively. Sequence analysis of 16S rRNA and groEL genes for Rickettsia spp. revealed 99 % identity  with Rickettsia felis. There were no dogs infected with A. phagocytophilum and Borrelia spp

    The ALHAMBRA survey : BB-band luminosity function of quiescent and star-forming galaxies at 0.2z<10.2 \leq z < 1 by PDF analysis

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    Our goal is to study the evolution of the BB-band luminosity function (LF) since z=1z=1 using ALHAMBRA data. We used the photometric redshift and the II-band selection magnitude probability distribution functions (PDFs) of those ALHAMBRA galaxies with I24I\leq24 mag to compute the posterior LF. We statistically studied quiescent and star-forming galaxies using the template information encoded in the PDFs. The LF covariance matrix in redshift-magnitude-galaxy type space was computed, including the cosmic variance. That was estimated from the intrinsic dispersion of the LF measurements in the 48 ALHAMBRA sub-fields. The uncertainty due to the photometric redshift prior is also included in our analysis. We modelled the LF with a redshift-dependent Schechter function affected by the same selection effects than the data. The measured ALHAMBRA LF at 0.2z<10.2\leq z<1 and the evolving Schechter parameters both for quiescent and star-forming galaxies agree with previous results in the literature. The estimated redshift evolution of MBQzM_B^* \propto Qz is QSF=1.03±0.08Q_{\rm SF}=-1.03\pm0.08 and QQ=0.80±0.08Q_{\rm Q}=-0.80\pm0.08, and of logϕPz\log \phi^* \propto Pz is PSF=0.01±0.03P_{\rm SF}=-0.01\pm0.03 and PQ=0.41±0.05P_{\rm Q}=-0.41\pm0.05. The measured faint-end slopes are αSF=1.29±0.02\alpha_{\rm SF}=-1.29\pm0.02 and αQ=0.53±0.04\alpha_{\rm Q}=-0.53\pm0.04. We find a significant population of faint quiescent galaxies, modelled by a second Schechter function with slope β=1.31±0.11\beta=-1.31\pm0.11. We find a factor 2.55±0.142.55\pm0.14 decrease in the luminosity density jBj_B of star-forming galaxies, and a factor 1.25±0.161.25\pm0.16 increase in the jBj_B of quiescent ones since z=1z=1, confirming the continuous build-up of the quiescent population with cosmic time. The contribution of the faint quiescent population to jBj_B increases from 3% at z=1z=1 to 6% at z=0z=0. The developed methodology will be applied to future multi-filter surveys such as J-PAS.Comment: Accepted for publication in Astronomy and Astrophysics. 25 pages, 20 figures, 7 table

    Metric-based vs peer-reviewed evaluation of a research output: Lesson learnt from UK’s national research assessment exercise

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    Purpose There is a general inquisition regarding the monetary value of a research output, as a substantial amount of funding in modern academia is essentially awarded to good research presented in the form of journal articles, conferences papers, performances, compositions, exhibitions, books and book chapters etc., which, eventually leads to another question if the value varies across different disciplines. Answers to these questions will not only assist academics and researchers, but will also help higher education institutions (HEIs) make informed decisions in their administrative and research policies. Design and methodology To examine both the questions, we applied the United Kingdom’s recently concluded national research assessment exercise known as the Research Excellence Framework (REF) 2014 as a case study. All the data for this study is sourced from the openly available publications which arose from the digital repositories of REF’s results and HEFCE’s funding allocations. Findings A world leading output earns between £7504 and £14,639 per year within the REF cycle, whereas an internationally excellent output earns between £1876 and £3659, varying according to their area of research. Secondly, an investigation into the impact rating of 25315 journal articles submitted in five areas of research by UK HEIs and their awarded funding revealed a linear relationship between the percentage of quartile-one journal publications and percentage of 4* outputs in Clinical Medicine, Physics and Psychology/Psychiatry/Neuroscience UoAs, and no relationship was found in the Classics and Anthropology/Development Studies UoAs, due to the fact that most publications in the latter two disciplines are not journal articles. Practical implications The findings provide an indication of the monetary value of a research output, from the perspectives of government funding for research, and also what makes a good output, i.e. whether a relationship exists between good quality output and the source of its publication. The findings may also influence future REF submission strategies in HEIs and ascertain that the impact rating of the journals is not necessarily a reflection of the quality of research in every discipline, and this may have a significant influence on the future of scholarly communications in general. Originality According to the author’s knowledge, this is the first time an investigation has estimated the monetary value of a good research output

    The Large Magellanic Cloud stellar content with SMASH I. Assessing the stability of the Magellanic spiral arms

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    The Large Magellanic Cloud (LMC) is the closest and most studied example of an irregular galaxy. Among its principal defining morphological features, its off-centred bar and single spiral arm stand out, defining a whole family of galaxies known as the Magellanic spirals (Sm). These structures are thought to be triggered by tidal interactions and possibly maintained via gas accretion. However, it is still unknown whether they are long-lived stable structures. In this work, by combining photometry that reaches down to the oldest main sequence turn-off in the colour-magnitude diagrams (CMD, up to a distance of ∼4.4 kpc from the LMC centre) from the SMASH survey and CMD fitting techniques, we find compelling evidence supporting the long-term stability of the LMC spiral arm, dating the origin of this structure to more than 2 Gyr ago. The evidence suggests that the close encounter between the LMC and the Small Magellanic Cloud (SMC) that produced the gaseous Magellanic Stream and its Leading Arm also triggered the formation of the LMC’s spiral arm. Given the mass difference between the Clouds and the notable consequences of this interaction, we can speculate that this should have been one of their closest encounters. These results set important constraints on the timing of LMC-SMC collisions, as well as on the physics behind star formation induced by tidal encounters.AEI/FEDER, UE AYA201789076-P AYA2016-77237-C3-1-P AYA2015-63810-PMinisterio de Ciencia, Innovacion y Universidades (MCIU), through Juan de la Cierva - Formacion grant FJCI-2016-30342Consejeria de Economia, Industria, Comercio y Conocimiento of the Canary Islands Autonomous Community, through Regional BudgetSpanish Public State Employment Service (SEPE)National Science Foundation (NSF) AST 1655677 AST-1909497Premiale INAF "MITIC"Ministry of Economy and Competitiveness of Spain AYA201342781PINFN (Iniziativa specifica TAsP)European Research Council (ERC) 682115"Centre of Excellence Severo Ochoa" award SEV-2017-0709Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 1181797Max Planck Society through a Partner Group grantComision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT PIA/BASAL AFB-170002Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 1170364AYA2016-81065-C2-2PGC2018-095049-B-C2
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