Aspectos genéticos del virus del dengue

El dengue es un virus endémico en regiones tropicales, que está asociado a las precipitaciones, temperatura, urbanización y distribución de su principal vector, Aedes aegypti. La carga mundial de esta enfermedad no es bien conocida, pero sus patrones epidemiológicos son alarmantes tanto para los seres humanos, la salud y economía global. El dengue se ha identificado como una enfermedad del futuro debido a las tendencias hacia el aumento de la urbanización, la escasez de agua y, posiblemente, el cambio ambiental. La transmisión de este virus se reporta principalmente en las regiones del Mediterráneo Oriental, América, Asia Sudoriental, Pacífico Occidental y África. A partir del conocimiento del genoma del dengue se puede conocer más a detalles el posible comportamiento de esta enfermedad incidente. La creación de moléculas terapéuticas y la toma de decisiones en la clínica se basan en el conocimiento acerca de los aspectos genéticos del virus, pues a este nivel se puede medir la virulencia y patogenicidad del mismo. En este sentido, el objetivo de este trabajo fue describir los elementos más importantes del virus, su distribución génica, los elementos de resistencia conferido por su estructura a nivel intracelular y el ciclo replicativo respectivo de esta familia viral. Palabras clave: Virus, dengue, regiones no codificantes, virus ARN, genes virales

The WiggleZ Dark Energy Survey: Star-formation in UV-luminous galaxies from their luminosity functions

We present the ultraviolet (UV) luminosity function of galaxies from the GALEX Medium Imaging Survey with measured spectroscopic redshifts from the first data release of the WiggleZ Dark Energy Survey. This sample selects galaxies with high star formation rates: at 0.6 < z < 0.9 the median star formation rate is at the upper 95th percentile of optically-selected (r<22.5) galaxies and the sample contains about 50 per cent of all NUV < 22.8, 0.6 < z < 0.9 starburst galaxies within the volume sampled. The most luminous galaxies in our sample (-21.0>M_NUV>-22.5) evolve very rapidly with a number density declining as (1+z)^{5\pm 1} from redshift z = 0.9 to z = 0.6. These starburst galaxies (M_NUV<-21 is approximately a star formation rate of 30 \msuny) contribute about 1 per cent of cosmic star formation over the redshift range z=0.6 to z=0.9. The star formation rate density of these very luminous galaxies evolves rapidly, as (1+z)^{4\pm 1}. Such a rapid evolution implies the majority of star formation in these large galaxies must have occurred before z = 0.9. We measure the UV luminosity function in 0.05 redshift intervals spanning 0.1<z<0.9, and provide analytic fits to the results. At all redshifts greater than z=0.55 we find that the bright end of the luminosity function is not well described by a pure Schechter function due to an excess of very luminous (M_NUV<-22) galaxies. These luminosity functions can be used to create a radial selection function for the WiggleZ survey or test models of galaxy formation and evolution. Here we test the AGN feedback model in Scannapieco et al. (2005), and find that this AGN feedback model requires AGN feedback efficiency to vary with one or more of the following: stellar mass, star formation rate and redshift.Comment: 27 pages; 13 pages without appendices. 22 figures; 11 figures in the main tex

COMPLICACIONES DE COVID-19 ASOCIADAS A LA OBESIDAD: REVISIÓN

Introducción: La interacción del hombre con los virus sigue siendo un amplio campo de estudio donde cada día hay novedades; en este sentido, con el reciente SARS-CoV-2 agente causal de la pandemia de COVID-19 se ha demostrado que determinadas condiciones inmunogenéticas, inflamatorias y cardio-metabólicas constituyen factores de riesgo para la forma de presentación complicada de la enfermedad, como se documentó en pacientes obesos. Objetivo: analizar y relacionar las complicaciones del COVID-19 asociadas a la obesidad y receptores inmunológicos. Métodos: Se llevó a cabo una búsqueda sistemática en las bases de datos PubMed, Embase, Redalyc, Springer y LILACS, tomando en cuenta artículos de revisión, artículos originales y revisiones sistemáticas publicadas en el contexto internacional; en el periodo febrero 2020 -febrero 2022. Se incluyó la revisión de 75 artículos en total: de los cuales se rechazaron 34 artículos por no contener la información a razón de búsqueda, resultando elegidos 41 artículos al cumplir con los criterios de elegibilidad. Resultados: La revisión bibliográfica sugiere la relación del estado inflamatorio crónico de bajo grado inducido por la obesidad y la infección por SARS-CoV-2. Conclusion: Es de suma importancia incrementar el número de investigaciones y/o reporte de casos en los cuales se incluyan pacientes con síndrome metabólico y obesidad resaltando además el amplio rango de receptores inmunes que se han descrito, sobre los cuales podrían diseñarse blancos terapéuticos aunado a la compresión fisiopatológica que cada día demuestra ser una red compleja con fuerte base inmunopatológica.&nbsp; &nbsp; Palabras clave: Síndrome Respiratorio Agudo Severo, COVID-19, inflamación, obesidad. &nbsp; ABSTRACT Introduction: The interaction of man with viruses continues to be a broad field of study where there are new developments every day; In this sense, with the recent SARS-CoV-2 causal agent of the COVID-19 pandemic, it has been shown that certain immunogenic, inflammatory and cardio-metabolic conditions constitute risk factors for the complicated form of presentation of the disease, as shown documented in obese patients. Objective: to analyze and relate the complications of COVID-19 associated with obesity and immune receptors. Methods: A systematic search was carried out in the PubMed, Embase, Redalyc, Springer and LILACS databases, taking into account review articles, original articles and systematic reviews published in the international context; in the period February 2020-February 2022. A total of 75 articles were reviewed: of which 34 articles were rejected for not containing the information due to the search, resulting in 41 articles being chosen as they met the eligibility criteria. Results: The literature review suggests the relationship between the low-grade chronic inflammatory state induced by obesity and SARS-CoV-2 infection. Conclusion: It is extremely important to increase the number of investigations and/or case reports in which patients with metabolic syndrome and obesity are included, also highlighting the wide range of immune receptors that have been described, on which therapeutic targets could be designed together with the pathophysiological understanding that each day proves to be a complex network with a strong immunopathological basis. Keywords: Severe Acute Respiratory Syndrome, COVID-19, inflammation, obesity

Complicaciones Cardiovasculares asociadas a infección por SARS-CoV-2. Revisión Sistemática

El COVID-19 es una enfermedad que ha afectado a la población mundial, convirtiéndose en una de las peores pandemias de nuestra generación, representando un reto social y sanitario sin precedentes; afecta principalmente el sistema respiratorio, sin embargo, diversos estudios han demostrado el compromiso cardiovascular, generando preocupación, que se traduce en una mayor vulnerabilidad en los pacientes con patologías cardiovasculares subyacentes. Se ha establecido que la presencia de comorbilidades, como hipertensión, diabetes y enfermedad arterial coronaria, se asocian con tasas de mortalidad elevadas, afectando a pacientes cardiovasculares crónicos y causando alteraciones cardiovasculares en pacientes sin antecedentes, por lo cual es necesario el monitoreo de biomarcadores cardíacos para un mejor abordaje de la enfermedad. Estudios clínicos han evidenciado que la patología cardiovascular que principalmente se asocia al COVID-19 es la insuficiencia cardíaca (IC), que se manifiesta con un aumento en los niveles de troponina, miopericarditis, shock cardiogénico, lesión cardíaca aguda, trastornos de coagulación y trombosis, arritmias, además del síndrome coronario agudo y la enfermedad de Kawasaki. Este artículo es una revisión de las complicaciones cardíacas asociadas al COVID-19 y sus posibles mecanismos de acción, que permitan un mejor entendimiento por parte del personal médico y de salud (PROSPERO ID 316364

The WiggleZ Dark Energy Survey: improved distance measurements to z = 1 with reconstruction of the baryonic acoustic feature

We present significant improvements in cosmic distance measurements from the WiggleZ Dark Energy Survey, achieved by applying the reconstruction of the baryonic acoustic feature technique. We show using both data and simulations that the reconstruction technique can often be effective despite patchiness of the survey, significant edge effects and shot-noise. We investigate three redshift bins in the redshift range 0.2 < z < 1, and in all three find improvement after reconstruction in the detection of the baryonic acoustic feature and its usage as a standard ruler. We measure model-independent distance measures DV(rsfid/rs) of 1716 ± 83, 2221 ± 101, 2516 ± 86 Mpc (68 per cent CL) at effective redshifts z = 0.44, 0.6, 0.73, respectively, where DV is the volume-averaged distance, and rs is the sound horizon at the end of the baryon drag epoch. These significantly improved 4.8, 4.5 and 3.4 per cent accuracy measurements are equivalent to those expected from surveys with up to 2.5 times the volume of WiggleZ without reconstruction applied. These measurements are fully consistent with cosmologies allowed by the analyses of the Planck Collaboration and the Sloan Digital Sky Survey. We provide the DV(rsfid/rs) posterior probability distributions and their covariances. When combining these measurements with temperature fluctuations measurements of Planck, the polarization of Wilkinson Microwave Anisotropy Probe 9, and the 6dF Galaxy Survey baryonic acoustic feature, we do not detect deviations from a flat Λ cold dark matter (ΛCDM) model. Assuming this model, we constrain the current expansion rate to H₀ = 67.15 ± 0.98 km s⁻¹Mpc⁻¹. Allowing the equation of state of dark energy to vary, we obtain wDE = −1.080 ± 0.135. When assuming a curved ΛCDM model we obtain a curvature value of ΩK = −0.0043 ± 0.0047

The WiggleZ Dark Energy Survey: the growth rate of cosmic structure since redshift z=0.9

We present precise measurements of the growth rate of cosmic structure for the redshift range 0.1 < z < 0.9, using redshift-space distortions in the galaxy power spectrum of the WiggleZ Dark Energy Survey. Our results, which have a precision of around 10% in four independent redshift bins, are well-fit by a flat LCDM cosmological model with matter density parameter Omega_m = 0.27. Our analysis hence indicates that this model provides a self-consistent description of the growth of cosmic structure through large-scale perturbations and the homogeneous cosmic expansion mapped by supernovae and baryon acoustic oscillations. We achieve robust results by systematically comparing our data with several different models of the quasi-linear growth of structure including empirical models, fitting formulae calibrated to N-body simulations, and perturbation theory techniques. We extract the first measurements of the power spectrum of the velocity divergence field, P_vv(k), as a function of redshift (under the assumption that P_gv(k) = -sqrt[P_gg(k) P_vv(k)] where g is the galaxy overdensity field), and demonstrate that the WiggleZ galaxy-mass cross-correlation is consistent with a deterministic (rather than stochastic) scale-independent bias model for WiggleZ galaxies for scales k < 0.3 h/Mpc. Measurements of the cosmic growth rate from the WiggleZ Survey and other current and future observations offer a powerful test of the physical nature of dark energy that is complementary to distance-redshift measures such as supernovae and baryon acoustic oscillations.Comment: 17 pages, 11 figures, accepted for publication by MNRA

The WiggleZ Dark Energy Survey: measuring the cosmic expansion history using the Alcock-Paczynski test and distant supernovae

Astronomical observations suggest that today's Universe is dominated by a dark energy of unknown physical origin. One of the most notable consequences in many models is that dark energy should cause the expansion of the Universe to accelerate: but the expansion rate as a function of time has proven very difficult to measure directly. We present a new determination of the cosmic expansion history by combining distant supernovae observations with a geometrical analysis of large-scale galaxy clustering within the WiggleZ Dark Energy Survey, using the Alcock-Paczynski test to measure the distortion of standard spheres. Our result constitutes a robust and non-parametric measurement of the Hubble expansion rate as a function of time, which we measure with 10-15% precision in four bins within the redshift range 0.1 < z < 0.9. We demonstrate that the cosmic expansion is accelerating, in a manner independent of the parameterization of the cosmological model (although assuming cosmic homogeneity in our data analysis). Furthermore, we find that this expansion history is consistent with a cosmological-constant dark energy.Comment: 13 pages, 7 figures, accepted for publication by MNRA

Do ResearchGate Scores create ghost academic reputations?

[EN] The academic social network site ResearchGate (RG) has its own indicator, RG Score, for its members. The high profile nature of the site means that the RG Score may be used for recruitment, promotion and other tasks for which researchers are evaluated. In response, this study investigates whether it is reasonable to employ the RG Score as evidence of scholarly reputation. For this, three different author samples were investigated. An outlier sample includes 104 authors with high values. A Nobel sample comprises 73 Nobel winners from Medicine and Physiology, Chemistry, Physics and Economics (from 1975 to 2015). A longitudinal sample includes weekly data on 4 authors with different RG Scores. The results suggest that high RG Scores are built primarily from activity related to asking and answering questions in the site. In particular, it seems impossible to get a high RG Score solely through publications. Within RG it is possible to distinguish between (passive) academics that interact little in the site and active platform users, who can get high RG Scores through engaging with others inside the site (questions, answers, social networks with influential researchers). Thus, RG Scores should not be mistaken for academic reputation indicators.Alberto Martin-Martin enjoys a four-year doctoral fellowship (FPU2013/05863) granted by the Ministerio de Educacion, Cultura, y Deporte (Spain). Enrique Orduna-Malea holds a postdoctoral fellowship (PAID-10-14), from the Polytechnic University of Valencia (Spain).Orduña Malea, E.; Martín-Martín, A.; Thelwall, M.; Delgado-López-Cózar, E. (2017). Do ResearchGate Scores create ghost academic reputations?. Scientometrics. 112(1):443-460. https://doi.org/10.1007/s11192-017-2396-9S4434601121Bosman, J. & Kramer, B. (2016). Innovations in scholarly communication—data of the global 2015–2016 survey. Available at: http://zenodo.org/record/49583 #. 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The evolution of research activity in Spain: The impact of the National Commission for the Evaluation of Research Activity (CNEAI). Research Policy, 32(1), 123–142.Jordan, K. (2014a). Academics’ awareness, perceptions and uses of social networking sites: Analysis of a social networking sites survey dataset (December 3, 2014). Available at: http://dx.doi.org/10.2139/ssrn.2507318 . Accessed December 11, 2016.Jordan, K. (2014b). Academics and their online networks: Exploring the role of academic social networking sites. First Monday, 19(11). Available at: http://dx.doi.org/10.5210/fm.v19i11.4937 . Accessed December 11, 2016.Jordan, K. (2015). Exploring the ResearchGate score as an academic metric: reflections and implications for practice. Quantifying and Analysing Scholarly Communication on the Web (ASCW’15), 30 June 2015, Oxford. Available at: http://ascw.know-center.tugraz.at/wp-content/uploads/2015/06/ASCW15_jordan_response_kraker-lex.pdf . Accessed December 11, 2016.Kadriu, A. (2013). Discovering value in academic social networks: A case study in ResearchGate. Proceedings of the ITI 2013—35th Int. Conf. on Information Technology Interfaces Information Technology Interfaces, pp. 57–62.Kraker, P. & Lex, E. (2015). A critical look at the ResearchGate score as a measure of scientific reputation. Proceedings of the Quantifying and Analysing Scholarly Communication on the Web workshop (ASCW’15), Web Science conference 2015. Available at: http://ascw.know-center.tugraz.at/wp-content/uploads/2016/02/ASCW15_kraker-lex-a-critical-look-at-the-researchgate-score_v1-1.pdf . Accessed December 11, 2016.Li, L., He, D., Jeng, W., Goodwin, S. & Zhang, C. (2015). Answer quality characteristics and prediction on an academic Q&A Site: A case study on ResearchGate. Proceedings of the 24th International Conference on World Wide Web Companion, pp. 1453–1458.Martín-Martín, A., Orduna-Malea, E., Ayllón, J. M. & Delgado López-Cózar, E. (2016). The counting house: measuring those who count. Presence of Bibliometrics, Scientometrics, Informetrics, Webometrics and Altmetrics in the Google Scholar Citations, ResearcherID, ResearchGate, Mendeley & Twitter. Available at: https://arxiv.org/abs/1602.02412 . Accessed December 11, 2016.Martín-Martín, A., Orduna-Malea, E. & Delgado López-Cózar, E. (2016). The role of ego in academic profile services: Comparing Google Scholar, ResearchGate, Mendeley, and ResearcherID. Researchgate, Mendeley, and Researcherid. The LSE Impact of Social Sciences blog. Available at: http://blogs.lse.ac.uk/impactofsocialsciences/2016/03/04/academic-profile-services-many-mirrors-and-faces-for-a-single-ego . Accessed December 11, 2016.Matthews, D. (2016). Do academic social networks share academics’ interests?. Times Higher Education. Available at: https://www.timeshighereducation.com/features/do-academic-social-networks-share-academics-interests . Accessed December 11, 2016.Memon, A. R. (2016). ResearchGate is no longer reliable: leniency towards ghost journals may decrease its impact on the scientific community. Journal of the Pakistan Medical Association, 66(12), 1643–1647.Mikki, S., Zygmuntowska, M., Gjesdal, Ø. L. & Al Ruwehy, H. A. (2015). Digital presence of norwegian scholars on academic network sites-where and who are they?. Plos One 10(11). Available at: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0142709 . Accessed December 11, 2016.Nicholas, D., Clark, D., & Herman, E. (2016). ResearchGate: Reputation uncovered. Learned Publishing, 29(3), 173–182.Orduna-Malea, E., Martín-Martín, A., & Delgado López-Cózar, E. (2016). The next bibliometrics: ALMetrics (Author Level Metrics) and the multiple faces of author impact. El profesional de la información, 25(3), 485–496.Ortega, Jose L. (2015). Relationship between altmetric and bibliometric indicators across academic social sites: The case of CSIC’s members. Journal of informetrics, 9(1), 39–49.Ortega, Jose L. (2016). Social network sites for scientists. Cambridge: Chandos.Ovadia, S. (2014). ResearchGate and Academia. edu: Academic social networks. Behavioral & Social Sciences Librarian, 33(3), 165–169.Thelwall, M., & Kousha, K. (2015). ResearchGate: Disseminating, communicating, and measuring Scholarship? Journal of the Association for Information Science and Technology, 66(5), 876–889.Thelwall, M. & Kousha, K. (2017). ResearchGate articles: Age, discipline, audience size and impact. Journal of the Association for Information Science and Technology, 68(2), 468–479.Van Noorden, R. (2014). Online collaboration: Scientists and the social network. Nature, 512(7513), 126–129.Wilsdon, J., Allen, L., Belfiore, E., Campbell, P., Curry, S., Hill, S. et al. (2015). The Metric Tide: Independent Review of the Role of Metrics in Research Assessment and Management. HEFCE. Available at: http://doi.org/10.13140/RG.2.1.4929.1363 . Accessed December 11, 2016

The WiggleZ Dark Energy Survey: the transition to large-scale cosmic homogeneity

We have made the largest-volume measurement to date of the transition to large-scale homogeneity in the distribution of galaxies. We use the WiggleZ survey, a spectroscopic survey of over 200,000 blue galaxies in a cosmic volume of ~1 (Gpc/h)^3. A new method of defining the 'homogeneity scale' is presented, which is more robust than methods previously used in the literature, and which can be easily compared between different surveys. Due to the large cosmic depth of WiggleZ (up to z=1) we are able to make the first measurement of the transition to homogeneity over a range of cosmic epochs. The mean number of galaxies N(<r) in spheres of comoving radius r is proportional to r^3 within 1%, or equivalently the fractal dimension of the sample is within 1% of D_2=3, at radii larger than 71 \pm 8 Mpc/h at z~0.2, 70 \pm 5 Mpc/h at z~0.4, 81 \pm 5 Mpc/h at z~0.6, and 75 \pm 4 Mpc/h at z~0.8. We demonstrate the robustness of our results against selection function effects, using a LCDM N-body simulation and a suite of inhomogeneous fractal distributions. The results are in excellent agreement with both the LCDM N-body simulation and an analytical LCDM prediction. We can exclude a fractal distribution with fractal dimension below D_2=2.97 on scales from ~80 Mpc/h up to the largest scales probed by our measurement, ~300 Mpc/h, at 99.99% confidence.Comment: 21 pages, 16 figures, accepted for publication in MNRA

Presencia de lesiones preinvasoras e invasoras de cérvix, relación con el virus papiloma humano y factores epidemiológicos en Mérida, Venezuela

&nbsp; Las lesiones de cérvix se han asociado a infección por Virus Papiloma Humano (VPH). 300 mujeres mayores de quince años que acudieron al Hospital Universitario de Los Andes (HULA), fueron estudiadas para identificar lesiones, detectar y tipificar VPH, y determinar factores asociados. Se realizó citología, colposcopia, cepillados cervicales utilizando (DNA collection device Digene®) y biopsias en los casos pertinentes. Se aisló el ADN mediante (QIAamp DNA Mini Kit QIAGEN®), siendo cuantificado y almacenado a -20 ºC. Se detectó VPH por Reacción en Cadena de la Polimerasa (PCR) de regiones L1 y E6/E7. La genotipificación por PCR anidada múltiple E6/E7, C. trachomatis se detectó por PCR. El VPH se detectó en 35 % (105) muestras, 88,46 % (92/105) fueron positivas para al menos uno de los genotipos evaluados. VPHAR se encontraron en 97,82 %, (90/92), VPH18 en 82 % (74/90), VPH16 en 44 % (40/90). 56,52 % (52/92) correspondieron a infecciones múltiples, VPH18/16 (20/52) fue la más frecuente. C. trachomatis se detectó en 9 % (27/300) pacientes. La citología mostró cambios sugestivos de infección en solo 16,35 % de las pacientes VPH positivas. 17/18 biopsias sugirieron infección viral y fueron positivas para VPH AR por biología molecular (94,44 %). La colposcopia sugirió infección viral en 46,15 %. El 66,34 % de pacientes fueron menores de 35 años. Se encontró relación estadísticamente no significativa entre infección por VPH, número de parejas sexuales, coinfección con C. trachomatis y hábito tabáquico. Estos resultados muestran elevada frecuencia de infección por VPH AR, asociada a factores epidemiológicos, cuyo diagnóstico certero y tratamiento oportuno son claves en la prevención de su transmisión y del desarrollo de lesiones en cérvix. &nbsp; Palabras clave: Cáncer cervical, virus papiloma humano, reacción en cadena de la polimerasa. &nbsp; Abstract &nbsp; Cervical lesions have been associated with infection by Human Papilloma Virus (HPV). Three hundred women older than 15 years old who attended at the Hospital Universidad de Los Andes (HULA), were studied to identify lesions, detect and typify HPV, and determine associated factors. Cytology, colposcopy, cervical brushing using (DNA collection device Digene®) and biopsies were performed in the pertinent cases. DNA was isolated by (QIAamp DNA Mini Kit QIAGEN®), being quantified and stored at -20 ° C. HPV was detected by Polymerase Chain Reaction (PCR) of regions L1 and E6 / E7. The genotyping by multiple nested PCR E6 / E7, C. trachomatis was detected by PCR. HPV was detected in 35% (105) samples, 88.46% (92/105) were positive for at least one of the genotypes evaluated. VPHAR were found in 97.82% (90/92), HPV18 in 82% (74/90), HPV16 in 44% (40/90). 56.52% (52/92) corresponded to multiple infections, HPV18 / 16 (20/52) was the most frequent. C. trachomatis was detected in 9% (27/300) patients. The cytology showed changes suggestive of infection in only 16.35% of the HPV positive patients. 17/18 biopsies suggested viral infection and were positive for ARV HPV by molecular biology (94.44%). Colposcopy suggested viral infection in 46.15%. 66.34% of patients were under 35 years old. A statistically non-significant relationship was found between HPV infection, number of sexual partners, coinfection with C. trachomatis and smoking habit. These results show high frequency of infection by HPV AR, associated with epidemiological factors, whose accurate diagnosis and timely treatment are key in the prevention of its transmission and the development of lesions in the cervix. &nbsp; Keywords: Cervical cancer, human papilloma virus, polymerase chain reaction