55 research outputs found
Técnicas de creación y manipulación de imágenes de estructuras orgánicas tridimensionales. Nuevos entornos de aplicación didáctica
The development of computer-generated images opens new perspectives in the field of teaching. These techniques permit geometric modelling of three-dimensional structures, allowing the production and manipulation of real images and the numerical and graphic characterization of two-three-dimensional contours. The procedure proposed is based on the manipulation, by geometric (turns, traslations) and algebraic (addition, intersection) operations, of an initially finite set of surfaces (elipsoids, paraboloids, cylinders and planes), defined by their parameters, for teaching purposes
Characterization of GFAP expression and cell proliferation in the rat median eminence following hypophysectomy
[EN]To analyze whether the reorganization of the
rat median eminence after hypophysectomy might be
related to changes in glial fibrillary acidic protein
(GFAP)- and cellular proliferation, the distribution of
cells immunoreactive for GFAP and the proliferation rate
of such cells were analyzed at 20, 40 and 60 days posthypophysectomy.
For this study, four rostro-caudal
regions of the median eminence were differentiated: the
retrochiasmatic, preinfundibular, infundibular and
postinfundibular regions. In each of these regions, three
layers were studied: the ependymal, the internal and the
external. At 20 and 40 days after hypophysectomy,
significant increases in cellular proliferation affecting all
three layers studied in the preinfundibular and
infundibular regions were found. At the same time
points, increases in GFAP expression were also
observed. However, after 60 days, GFAP and
proliferative cellular nuclear antigen (PCNA) expression
decreased. Although variations of PCNA and GFAP
levels were evident, no colocalisation of PCNA and
GFAP was found in the cells of the median eminence in
untreated or hypophysectomized rats when sections were
analyzed by double immunohistochemical staining. Our
results suggest that reorganization of median eminence
involves alterations (or modulation) of GFAPimmunoreactive
cells together with a proliferation of
cells that are not GFAP-immunoreactive. This study also
demonstrates that this reorganization is completed within
the first two months after hypophysectomy
A web application for the unspecific detection of differentially expressed DNA regions in strand-specific expression data
Genomic technologies allow laboratories to produce large-scale data sets, either through the use of next-generation sequencing or microarray platforms. To explore these data sets and obtain máximum value from the data, researchers view their results alongside all the known features of a given reference genome. To study transcriptional changes that occur under a given condition, researchers search for regions of the genome that are differentially expressed between different experimental conditions. In order to identify these regions several algorithms have been developed over the years, along with some bioinformatic platforms that enable their use. However, currently available applications for comparative microarray analysis exclusively focus on changes in gene expression within known transcribed regions of predicted proteincoding genes, the changes that occur in non-predictable genetic elements, such as non-coding RNAs. Here, we present a web application for the visualization of strand-specific tiling microarray or next-generation sequencing data that allows customized detection of differentially expressed regions all along the genome in an unspecific manner, that allows identification of all RNA sequences, predictable or no
Variations in the cellular proliferation of prolactin cells from late pregnancy to lactation in rats
[EN]Lactation is a physiological process associated
with hyperactivity of hypophyseal prolactin-producing
cells. It is known that the percentage of these cells is increased
during lactation, although there are discrepancies
in the reports regarding the mechanisms responsible for
increasing the number of prolactin cells. In order to analyse
whether this increase is a result of previous proliferation,
variations in the proliferation rate of prolactinpositive
cells were determined from late pregnancy to lactation
in adult female rats by means of observation of the
immunohistochemical expression of PCNA as a marker
of cellular proliferation. During late pregnancy, a very
significant increase in the percentage of proliferating prolactin
cells was observed in comparison to non-pregnant
females in the proestrus phase (p < 0.01). Although the
percentage of prolactin-positive cells after one week of
lactation was higher than in non-lactating or in pregnant
females (p < 0.01), the proliferation rate was lower than
in the other groups studied. In sum, our results suggest
that late pregnancy constitutes a preliminary proliferative
phase preparatory to the ensuing lactation phase and that
endocrine changes in late pregnancy involve the cellular
proliferation of hypophyseal prolactin cells in order to
prepare the gland for later demands and to prevent proliferative
changes from occurring during lactation
Advantages and insights from a hierarchical Bayesian growth and dynamics model based on salmonid electrofishing removal data
Growth is a fundamental ecological process of stream-dwelling salmonids which is strongly interrelated to critical life history events (emergence, mortality, sexual maturity, smolting, spawning). The ability to accurately model growth becomes critical when making population predictions over large temporal (multi-decadal) and spatial (meso) scales, e.g., investigating the effect of global change. Body length collection by removal sampling is a widely-used practice for monitoring fish populations over such large scales. Such data can be efficiently integrated into a Hierarchical Bayesian Model (HBM) and lead to interesting findings on fish dynamics. We illustrate this approach by presenting an integrated HBM of brown trout (Salmo trutta) growth, population dynamics, and removal sampling data collection processes using large temporal and spatial scales data (20 years; 48 sites placed along a 100 km latitudinal gradient). Growth and population dynamics are modelled by ordinary differential equations with parameters bound together in a hierarchical structure. The observation process is modelled with a combination of a Poisson error, a binomial error, and a mixture of Gaussian distributions. Absolute fit is measured using posterior predictive checks, which results indicate that our model fits the data well. Results indicate that growth rate is positively correlated to catchment area. This result corroborates those of other studies (laboratory, exploratory) that identified factors besides water temperature that are related to daily ration and have a significant effect on stream-dwelling salmonid growth at a large scale. Our study also illustrates the value of integrated HBM and electrofishing removal sampling data to study in situ fish populations over large scales
Pretreatment of urine samples with SDS improves direct identification of urinary tract pathogens with matrix-assisted laser desorption ionization-time of flight mass spectrometry
[EN]We pretreated with SDS 71 urine samples with bacterial counts of >10(5) CFU/ml and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) identification scores of <2, in order to minimize failure rates. Identification improved in 46.5% of samples, remained unchanged in 49.3%, and worsened in 4.2%. The improvement was more evident for Gram-negative (54.3%) than for Gram-positive (32%) bacteria
Drivers of variability in Blue Carbon stocks and burial rates across European estuarine habitats
The implementation of climate change mitigation strategies based on the conservation and restoration of Blue Carbon ecosystems requires a deep understanding of the magnitude and variability in organic carbon (Corg) storage across and within these ecosystems. This study explored the variability in soil Corg stocks and burial rates across and within intertidal estuarine habitats of the Atlantic European coast and its relation to biotic and abiotic drivers. A total of 136 soil cores were collected across saltmarshes located at different tidal zones (high marsh, N = 45; low marsh, N = 30), seagrass meadows (N = 17) and tidal flats (N = 44), and from the inner to the outer sections of five estuaries characterized by different basin land uses. Soil Corg stocks were higher in high-marsh communities (65 ± 3 Mg ha−1) than in low-marsh communities (38 ± 3 Mg ha−1), seagrass meadows (40 ± 5 Mg ha−1) and unvegetated tidal flats (46 ± 3 Mg ha−1) whereas Corg burial rates also tended to be higher in high marshes (62 ± 13 g m−2 y−1) compared to low marshes (43 ± 15 g m−2 y−1) and tidal flats (35 ± 9 g m−2 y−1). Soil Corg stocks and burial rates decreased from inner to outer estuarine sections in most estuaries reflecting the decrease in the river influence towards the estuary mouth. Higher soil Corg stocks were related to higher content of silt and clay and higher proportion of forest and natural land within the river basin, pointing at new opportunities for protecting coastal natural carbon sinks based on the conservation and restoration of upland ecosystems. Our study contributes to the global inventory of Blue Carbon by adding data from unexplored regions and habitats in Europe, and by identifying drivers of variability across and within estuaries
Thermal and thermo-oxidative stability and kinetics of decomposition of PHBV/sisal composites
The decomposition behaviours of composites made of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and sisal were assessed in terms of thermal stability and decomposition kinetics, under inert and oxidative conditions, by means of multi-rate linear non-isothermal thermogravimetric experiments. A statistical design of experiments was applied to study the influence of the addition of sisal (0-10-20-30%wt), the presence coupling agent (Yes/No) and the applied conditions of work (inert or oxidative). An improvement of the thermal and thermo-oxidative stability of PHBV with the addition of sisal was observed for all cases. An accurate methodology based on iso-conversional methods was applied to simulate the potential of thermal recovery technologies, such as pyrolysis and controlled combustion, to use these biocomposites after the end of their service life. The mathematical descriptions of both thermo-chemical reactions were helpful in the evaluation of the eventual optimal operational conditions to carry out a suitable energetic valorisation. A minimum of 240°C and 137 kJ/mol of activation energy in inert conditions and 236°C and 118 kJ/mol in oxidative conditions ensured the feasibility of the reactions regardless the composition of the PHBV/sisal biocomposites, which may ease the operability of further energy valorisation with the aim to turn biowaste into new fuels
Drivers of variability in blue carbon stocks and burial rates across europeanestuarine habitats
The implementation of climate change mitigation strategies based on the conservation and restoration of Blue Carbon ecosystems requires a deep understanding of themagnitude and variability in organic carbon (Corg) storage across and within these ecosystems. This study explored the variability in soil Corg stocks and burial rates across and within intertidal estuarine habitats of the Atlantic European coast and its relation to biotic and abiotic drivers. A total of 136 soil cores were collected across saltmarshes located at different tidal zones (high marsh, N = 45; low marsh, N = 30), seagrass meadows (N=17) and tidal flats (N=44), and from the inner to the outer sections of five estuaries characterized by different basin land uses. Soil Corg stocks were higher in high-marsh communities (65±3 Mg ha-1) than in low-marsh communities (38 ±3 Mg ha-1), seagrass meadows (40 ± 5 Mg ha-1) and unvegetated tidal flats (46± 3Mg ha-1) whereas Corg burial rates also tended to be higher in highmarshes (62±13 g m-2 y-1) compared to low marshes (43 ± 15 g m-2 y-1) and tidal flats (35 ± 9 g m-2 y-1). Soil Corg stocks and burial rates decreased from inner to outer estuarine sections in most estuaries reflecting the decrease in the river influence towards the estuary mouth. Higher soil Corg stocks were related to higher content of silt and clay and higher proportion of forest and natural land within the river basin, pointing at new opportunities for protecting coastal natural carbon sinks based on the conservation and restoration of upland ecosystems. Our study contributes to the global inventory of Blue Carbon by adding data from unexplored regions and habitats in Europe, and by identifying drivers of variability across and within estuaries.The authors acknowledge the financial support fromthe Government of Cantabria through the “Fénix Programme”. IM was supported by a Juan de la Cierva Incorporación postdoctoral fellowship of the Spanish Ministry of Science, Innovation and Universities (JC2020-045917-I).OS was supported by I+D+i projects RYC2019-027073-I and PIE HOLOCENO 20213AT014 funded by the Spanish Ministry of Science, Innovation and Universities (MCIN/AEI/10.13039/501100011033) and FEDER. The IAEA is grateful for the support provided to its Marine Environment Laboratories by the Government of the Principality of Monaco. PM was supported by the
Australian Research Council. J.G.O. acknowledges the financial support of the Spanish Ministry of Science, Innovation and Universities, through the “Maria de Maeztu” program for Units of Excellence (CEX2019-000940-M)
and the Generalitat de Catalunya (MERS; 2017 SGR–1588). This research was carried out with the contribution of the LIFE Programme of the European Union to the Project ADAPTA BLUES (ref. LIFE18 CCA/ES/001160). This document reflects only the authors' view and the Agency/Commission is not responsible for any use that may be made of the information it contains
VISMapper: ultra-fast exhaustive cartography of viral insertion sites for gene therapy
Background -- The possibility of integrating viral vectors to become a persistent part of the host genome makes them a crucial element of clinical gene therapy. However, viral integration has associated risks, such as the unintentional activation of oncogenes that can result in cancer. Therefore, the analysis of integration sites of retroviral vectors is a crucial step in developing safer vectors for therapeutic use. Results -- Here we present VISMapper, a vector integration site analysis web server, to analyze next-generation sequencing data for retroviral vector integration sites. VISMapper can be found at: http://vismapper.babelomics.org. Conclusions -- Because it uses novel mapping algorithms VISMapper is remarkably faster than previous available programs. It also provides a useful graphical interface to analyze the integration sites found in the genomic context
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