Crosstalk between chromatin structure, cohesin activity and transcription

Background: A complex interplay between chromatin and topological machineries is critical for genome architec‑ ture and function. However, little is known about these reciprocal interactions, even for cohesin, despite its multiple roles in DNA metabolism. Results: We have used genome‑wide analyses to address how cohesins and chromatin structure impact each other in yeast. Cohesin inactivation in scc1‑73 mutants during the S and G2 phases causes specific changes in chromatin structure that preferentially take place at promoters; these changes include a significant increase in the occupancy of the − 1 and + 1 nucleosomes. In addition, cohesins play a major role in transcription regulation that is associated with specific promoter chromatin architecture. In scc1‑73 cells, downregulated genes are enriched in promoters with short or no nucleosome‑free region (NFR) and a fragile “nucleosome − 1/RSC complex” particle. These results, together with a preferential increase in the occupancy of nucleosome − 1 of these genes, suggest that cohesins promote transcription activation by helping RSC to form the NFR. In sharp contrast, the scc1‑73 upregulated genes are enriched in promoters with an “open” chromatin structure and are mostly at cohesin‑enriched regions, suggesting that a local accumulation of cohesins might help to inhibit transcription. On the other hand, a dramatic loss of chromatin integrity by histone depletion during DNA replication has a moderate effect on the accumulation and distribution of cohesin peaks along the genome. Conclusions: Our analyses of the interplay between chromatin integrity and cohesin activity suggest that cohesins play a major role in transcription regulation, which is associated with specific chromatin architecture and cohesin‑ mediated nucleosome alterations of the regulated promoters. In contrast, chromatin integrity plays only a minor role in the binding and distribution of cohesins.Spanish Ministry of Economy and Competitivenes BFU2012-38171, BFU2015-63698-PAndalusian Government P12-CTS-227

Reconstrucción de computador analógico de laboratorio de sistemas dinámicos y control de la Universidad Tecnológica de Pereira

En el Laboratorio de Sistemas Dinámicos y Control de la Universidad Tecnológica de Pereira, se contaba con un computador analógico mecánico no apto para el uso ya que presentaba elementos faltantes y averiados. Este dispositivo fue construido por los estudiantes de Ingeniería Mecánica Fernando Hoyos Gutiérrez y León Duque Orrego en el año de 1976. El computador se usó durante aproximadamente 10 años, momento en el cual presentó diferentes averías y no fue rehabilitado..

Limits of acceptable change of ecotourism in Punta del Este, Isla de la Juventud (Cuba)

Esta investigación está encaminada a estudiar las capacidades de carga o límites aceptables de cambio, en la cantidad de visitantes que puede soportar una actividad ecoturística en una zona determinada, para contribuir a la conservación del medioambiente mediante un desarrollo sostenible. En este caso, el estudio se realizó en la zona sur de la Isla de la Juventud (Cuba); concretamente en la denominada Punta del Este. Para ello se utilizó una metodología mixta basada en métodos descriptivos: analítico-sintético y lógico abstracto, así como mediante el análisis experimental basado en el método desarrollado por Cifuentes en 1992 y mejorado en 1999. La aportación de esta investigación ha sido la obtención de datos sobre el mayor impacto de visitantes, o capacidad de carga que puede soportar la zona en las caminatas ecoturísticas realizadas por el turismo nacional e internacional, a fin de poder analizar las posibilidades económicas que este tipo de actividades pueden aportar, conservando su carácter de economía sostenible y sin que se comprometa el medioambiente para que las futuras generaciones puedan disfrutar y admirar la belleza de los recursos naturales existentes.The aim of this research is to study the carrying capacity or limits of acceptable change with respect to the number of visitors that an ecotourism activity in a specific area can bear so as to contribute to environmental conservation through sustainable development. The area chosen for this study corresponds to the southern region of Isla de la Juventud (Cuba); particularly in the so-called Punta Este. A mixed methodology was used, combining different descriptive methods: Analytic-Synthetic and logical abstract methods, as well as the experimental analysis based on the method developed by Cifuentes in 1992 and improved in 1999. The principal contribution of this work is to provide data on the maximum visitor impact, or the carrying capacity that this area can bear as a result of the ecotourism walking tours undertaken by domestic and international tourists. This research aims to analyse the financial gains that these types of activities can provide, maintaining their sustainable economic nature without causing negative impacts to the environment so that future generations can enjoy and admire the beauty of the existing natural resources

Síntomas depresivos y funcionamiento cognitivo de las personas en proceso de reintegración mayores (PPRM) de Colombia

Some Senior Citizens in Reintegration Processes (PPRM), who participated in war have mental disturbances explained by the long de-schooling and living situations, which decrease the possibility of accessing the workforce and society. Altered cognitive functioning was more prevalent in people without formal education, without a partner, or living in non-functional families. Among the PPRM demographic factors of PPRM, which increase the likelihood of having a depressive symptom was belonging to the male sex, being over 65 years old, not having support from a partner. This likelihood decreases if there is any degree of schooling. Among the family and social factors discussed, only living with a non-functional family was found to increase the risk of depressive symptoms. Thus, accompaniment is required for the acceptance of their aging process, the use of experiences, and the exercise of citizenship.Algunas personas en procesos de reintegración mayores (PPRM) que participaron en la guerra presentan alteraciones mentales explicadas por el largo tiempo desescolarizados y las situaciones vividas, que le disminuyen la posibilidad de acceso al campo laboral y a la sociedad, el funcionamiento cognitivo alterado fue más prevalente en personas sin educación formal, sin pareja o vivir en familias no funcionales. Entre los factores demográficos de las PPRM que aumentan la probabilidad de tener un síntoma depresivo fue pertenecer al sexo masculino, tener más de 65 años, no contar con apoyo de una pareja y disminuye esta probabilidad si se cuenta con algún grado de escolaridad. De los factores familiares y sociales que se analizaron, solo se encontró que vivir con una familia no funcional aumenta el riesgo de sufrir síntomas depresivos. Por lo que se requiere acompañamiento para la aceptación de su proceso de envejecimiento, el aprovechamiento de experiencias y el ejercicio de la ciudadanía

Distribution of the heavy elements throughout the extended narrow line region of the Seyfert galaxy NGC 7212

The latest observations of line and continuum spectra emitted from the extended narrow line region (ENLR) of the Seyfert 2 galaxy NGC 7212 are analysed using models accounting for photoionization from the active nucleus and shocks. The results show that relatively high (500--800 \kms) shock velocities appear on the edge of the cone and outside of it. The model-inferred AGN flux, which is lower than $10^{-11}$ photons cm$^{-2}$ s$^{-1}$ eV$^{-1}$ at the Lyman limit, is more typical of low-luminosity AGN, and less so for Seyfert 2 galaxies. The preshock densities are characteristic of the ENLR and range between 80--150 cm$^{-3}$. Nitrogen and sulphur are found depleted by a factor lower than 2, particularly at the eastern edge. Oxygen is depleted at several locations. The Fe/H ratio is approximately solar, whereas the Ne/H relative abundance is unusually high, 1.5--2 times the solar value. Modelling the continuum spectral energy distribution (SED), we have found radio synchrotron radiation generated by the Fermi mechanism at the shock front, whereas the X-rays are produced by the bremsstrahlung from a relatively high temperature plasma.Comment: 17 pages, 14 figures, accepted for publication in A&

Floral scent changes in response to pollen removal are rare in buzz-pollinated Solanum

Main conclusion One of seven Solanum taxa studied displayed associations between pollen presence and floral scent composition and volume, suggesting buzz-pollinated plants rarely use scent as an honest cue for foraging pollinators. Abstract Floral scent influences the recruitment, learning, and behaviour of floral visitors. Variation in floral scent can provide information on the amount of reward available or whether a flower has been visited recently and may be particularly important in species with visually concealed rewards. In many buzz-pollinated flowers, tubular anthers opening via small apical pores (poricidal anthers) visually conceal pollen and appear similar regardless of pollen quantity within the anther. We investigated whether pollen removal changes floral scent composition and emission rate in seven taxa of buzz-pollinated Solanum (Solanaceae). We found that pollen removal reduced both the overall emission of floral scent and the emission of specific compounds (linalool and farnesol) in S. lumholtzianum. Our findings suggest that in six out of seven buzz-pollinated taxa studied here, floral scent could not be used as a signal by visitors as it does not contain information on pollen availability

Percepción de la sexualidad en personas mayores de 60 años. Medellín, Colombia

Sexuality is inherent and accompanies human beings throughout the course of life, transcends the sexual act, to address aspects of physical, emotional and cultural order. Objective. To analyze the factors associ- ated with the perception of sexuality according to demographic, emotional and psychological characteristics in people over 60 years of age. Materials and methods. A quantitative, analytical, observational study was conducted, with a primary source of information, to 665 people aged 60 and over, from the city of Medellin, in 2018. The demographic, emotional and psychological characteristics that allowed to know their percep- tion about sexuality. X2 association measures were calculated and as epidemiological measures, crude and adjusted prevalence ratios. Results. People who never felt sad considered sexuality important (69.4%), men with a stable partner, who do not feel alone, with social support also considered it important. Conclusions. The importance in the sexuality of the older person is determined by moods, emotional stability and social integration.La sexualidad es inherente y acompaña durante todo el curso de la vida a los seres humanos, trasciende el acto sexual para abordar aspectos de orden físico, emocional y cultural. Objetivo. Analizar los factores asociados a la percepción de la sexualidad según características demográficas, emocionales y psicológicas en personas mayores de 60 años. Materiales y métodos. Se realizó un estudio cuantitativo, observacional analítico, con fuente de información primaria a 665 personas de 60 años y más de la ciudad de Medellín, en el año 2018. Se determinaron las características demográficas, emocionales y psicológicas que permitieran conocer su percepción sobre sexualidad. Se calcularon medidas de asociación X2 y como medidas epide- miológicas, razones de prevalencia crudas y ajustadas. Resultados. Las personas que nunca se sintieron tristes consideraron importante la sexualidad (69,4 %), los hombres con una pareja estable, que no se sienten solos, con apoyo social también la consideraron como algo importante. Conclusiones. La importancia en la sexualidad de la persona mayor está determinada por estados anímicos, de estabilidad emocional y de integración social

Multiscale characterisation of chimneys/pipes: Fluid escape structures within sedimentary basins

Evaluation of seismic reflection data has identified the presence of fluid escape structures cross-cutting overburden stratigraphy within sedimentary basins globally. Seismically-imaged chimneys/pipes are considered to be possible pathways for fluid flow, which may hydraulically connect deeper strata to the seabed. The properties of fluid migration pathways through the overburden must be constrained to enable secure, long-term subsurface carbon dioxide (CO2) storage. We have investigated a site of natural active fluid escape in the North Sea, the Scanner pockmark complex, to determine the physical characteristics of focused fluid conduits, and how they control fluid flow. Here we show that a multi-scale, multi-disciplinary experimental approach is required for complete characterisation of fluid escape structures. Geophysical techniques are necessary to resolve fracture geometry and subsurface structure (e.g., multi-frequency seismics) and physical parameters of sediments (e.g., controlled source electromagnetics) across a wide range of length scales (m to km). At smaller (mm to cm) scales, sediment cores were sampled directly and their physical and chemical properties assessed using laboratory-based methods. Numerical modelling approaches bridge the resolution gap, though their validity is dependent on calibration and constraint from field and laboratory experimental data. Further, time-lapse seismic and acoustic methods capable of resolving temporal changes are key for determining fluid flux. Future optimisation of experiment resource use may be facilitated by the installation of permanent seabed infrastructure, and replacement of manual data processing with automated workflows. This study can be used to inform measurement, monitoring and verification workflows that will assist policymaking, regulation, and best practice for CO2 subsurface storage operations