86 research outputs found
Chromosomal Dynamics at the Shh Locus: Limb Bud-Specific Differential Regulation of Competence and Active Transcription
The expression of Sonic hedgehog (Shh) in mouse limb buds is regulated by a long-range enhancer 1 Mb upstream of the Shh promoter. We used 3D-FISH and chromosome conformation capture assays to track changes at the Shh locus and found that long-range promoter-enhancer interactions are specific to limb bud tissues competent to express Shh. However, the Shh locus loops out from its chromosome territory only in the posterior limb bud (zone of polarizing activity or ZPA), where Shh expression is active. Notably, while Shh mRNA is detected throughout the ZPA, enhancer-promoter interactions and looping out were only observed in small fractions of ZPA cells. In situ detection of nascent Shh transcripts and unstable EGFP reporters revealed that active Shh transcription is likewise only seen in a small fraction of ZPA cells. These results suggest that chromosome conformation dynamics at the Shh locus allow transient pulses of Shh transcription
Longitudinal study on factors affecting assertiveness among preceptors of novice nurses
Purpose: This study aims to understand the assertiveness of preceptors of novice nurses and factors affecting the assertiveness through a longitudinal perspective. Methods: Anonymous self-rating questionnaire surveys were administered to 1292 preceptors working in participating city and university hospitals across Japan (August, 2013 (baseline) and March, 2014 (second survey)). The surveys had question items from the Japanese version of the Rathus Assertiveness Schedule (J-RAS, 30 items), demographic details of the participants, evaluation of novice nurses by preceptors, instruction framework, selfevaluation of preceptors, working environment, and a burnout inventory (Japanese version of the Maslach Burnout InventoryHuman Services Survey, 22 items). Bivariate analyses (T-tests and one-way analysis of variance) were conducted using assertiveness of the second survey as the objective variable, and other items of the baseline survey as explanatory variables. Selecting variables with p values smaller than 0.2 obtained in the bivariate analysis as explanatory variables, a multiple linear regression analysis (Stepwise method) was conducted. For the analyses, we used a statistics analysis software, SPSS Statistic 22. Results: Choosing 836 valid respondents of the baseline survey as a cohort group, we repeated the survey 8 months after the baseline survey to identify the factors affecting the assertiveness of preceptors of novice nurses. Excluding 62 who had missing values in the question items for assertiveness, 472 participants who were followed were included in analyses. As the results, following factors were found to affect the assertiveness: thinking that ‘they make rapid decisions’, and that ‘they are valuable as others’. Further, participants who have higher total burnout scores had lower assertiveness. Adjusted coefficient of determination was 0.153. Discussion: It can be inferred that the assertiveness of preceptors is higher than that of novice nurses measured by the J-RAS used in this study, and lower than that of administrative nurses. The assertiveness of preceptors was higher among participants who evaluated themselves positively, thinking that ‘they make rapid decisions’, and that ‘they are valuable as others’. It was also found that higher ‘total burnout scores’ was a factor that lowers the assertiveness. These findings suggest that a positive self-evaluation improves assertiveness and helps to prevent burnou
Chromosomal Dynamics at the Shh Locus: Limb Bud-Specific Differential Regulation of Competence and Active Transcription
SummaryThe expression of Sonic hedgehog (Shh) in mouse limb buds is regulated by a long-range enhancer 1 Mb upstream of the Shh promoter. We used 3D-FISH and chromosome conformation capture assays to track changes at the Shh locus and found that long-range promoter-enhancer interactions are specific to limb bud tissues competent to express Shh. However, the Shh locus loops out from its chromosome territory only in the posterior limb bud (zone of polarizing activity or ZPA), where Shh expression is active. Notably, while Shh mRNA is detected throughout the ZPA, enhancer-promoter interactions and looping out were only observed in small fractions of ZPA cells. In situ detection of nascent Shh transcripts and unstable EGFP reporters revealed that active Shh transcription is likewise only seen in a small fraction of ZPA cells. These results suggest that chromosome conformation dynamics at the Shh locus allow transient pulses of Shh transcription
Management of Natural History collections: criteria and parameters of evaluation
[ES] Las colecciones de historia natural son una herramienta básica para la investigación
científica y el estudio de la distribución en el pasado de muchas especies, así como de
la propia historia de la ciencia. Además del uso científico de estas colecciones, destacan
otros como el histórico, el divulgativo-pedagógico y el estético. De ahí la importancia
que tiene una gestión eficaz de las mismas, la cual implica diversos aspectos, que van
desde la conservación y su mantenimiento, su inventario, ordenación y procesamiento
informático hasta las múltiples tareas relacionadas con su uso en consultas, visitas,
préstamos científicos y participación en actividades de carácter divulgativo. En este
artículo se examinan los criterios para evaluar la gestión de las colecciones de historia
natural y se definen una serie de parámetros, útiles para medir el estado de una colección
y su evolución en el tiempo, tanto en su crecimiento como en su uso, principalmente. Se
ejemplifica todo ello en el grupo de los poliquetos, del que el Museo Nacional de Ciencias
Naturales de Madrid (MNCN) cuenta con una estimable colección, y se comparan los
resultados, según varios parámetros seleccionados, con los de otras colecciones de
poliquetos de diversas instituciones de todo el mundo.[EN] Natural History collections are a basic and essential tool for scientific research,
the study of the distribution in the past of many species of animals and plants and the
History of Science. As well as the scientific aspect of these collections, stand outs other
uses as the historic one, the educational and the aesthetic. All these are reasons that
show the importance of an effective management of the Natural History collections as
well as the several tasks related to it, as consults, visits, scientific loans and educational
activities. In this article various criteria and useful parameters are provided for evaluating
the curatorial state of a Natural History collection and its evolution, both in growth
and use mainly. Finally, an example based on the Polychaeta, an estimable group in
the Invertebrates Collection of the Museo Nacional de Ciencias Naturales of Madrid
(MNCN), is provided. The results of several selected parameters are compared with
other Polychaeta collections from several institutions around the world.Peer reviewe
The ASTRO-H X-ray Observatory
The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly
successful X-ray missions initiated by the Institute of Space and Astronautical
Science (ISAS). ASTRO-H will investigate the physics of the high-energy
universe via a suite of four instruments, covering a very wide energy range,
from 0.3 keV to 600 keV. These instruments include a high-resolution,
high-throughput spectrometer sensitive over 0.3-2 keV with high spectral
resolution of Delta E < 7 eV, enabled by a micro-calorimeter array located in
the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers
covering 5-80 keV, located in the focal plane of multilayer-coated, focusing
hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12
keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and
a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the
40-600 keV band. The simultaneous broad bandpass, coupled with high spectral
resolution, will enable the pursuit of a wide variety of important science
themes.Comment: 22 pages, 17 figures, Proceedings of the SPIE Astronomical
Instrumentation "Space Telescopes and Instrumentation 2012: Ultraviolet to
Gamma Ray
The Quiescent Intracluster Medium in the Core of the Perseus Cluster
Clusters of galaxies are the most massive gravitationally-bound objects in
the Universe and are still forming. They are thus important probes of
cosmological parameters and a host of astrophysical processes. Knowledge of the
dynamics of the pervasive hot gas, which dominates in mass over stars in a
cluster, is a crucial missing ingredient. It can enable new insights into
mechanical energy injection by the central supermassive black hole and the use
of hydrostatic equilibrium for the determination of cluster masses. X-rays from
the core of the Perseus cluster are emitted by the 50 million K diffuse hot
plasma filling its gravitational potential well. The Active Galactic Nucleus of
the central galaxy NGC1275 is pumping jetted energy into the surrounding
intracluster medium, creating buoyant bubbles filled with relativistic plasma.
These likely induce motions in the intracluster medium and heat the inner gas
preventing runaway radiative cooling; a process known as Active Galactic
Nucleus Feedback. Here we report on Hitomi X-ray observations of the Perseus
cluster core, which reveal a remarkably quiescent atmosphere where the gas has
a line-of-sight velocity dispersion of 164+/-10 km/s in a region 30-60 kpc from
the central nucleus. A gradient in the line-of-sight velocity of 150+/-70 km/s
is found across the 60 kpc image of the cluster core. Turbulent pressure
support in the gas is 4% or less of the thermodynamic pressure, with large
scale shear at most doubling that estimate. We infer that total cluster masses
determined from hydrostatic equilibrium in the central regions need little
correction for turbulent pressure.Comment: 31 pages, 11 Figs, published in Nature July
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