79 research outputs found

    Glacier movement prediction through computer vision and satellite imagery

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    Over the last decade, climate change has impacted Earths' atmosphere and environment more than anytime before. Glaciers are the most sensitive indicators of its impact. In this work, we model a glacier's evolution by applying computer vision algorithms on high-resolution satellite imagery. We detect changes in the ice coverage movement by applying a dense optical flow algorithm over an image time series covering a particular scene (region) and processed to extract the NDSI. We perform tests on the Jungfrau-Aletsch-Bietschhorn (JAB) glacier in the Swiss Alps. Our results show that we are able to obtain relevant information by computing motion vectors across time. Furthermore, we observe small differences between our predicted NDSI and the observed values demonstrating the efficiency of the approach

    Quantitative characterisation of extended-release tablets with quetiapine using NIR-chemometric methods

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    This study aims to develop and validate NIR-chemometric methods for quantifying the API (quetiapine) and two excipients in extended-release tablets without sample preparation. The calibration samples were prepared following an experimental design with three variables (quetiapine, HPMC and microcrystalline cellulose) and five levels (concentration 80-90-100-110-120% of API). The validation set included three concentration levels (90-100-110%). The best calibration algorithms have used the same pre-treatment method (SNV), and different factors: 7 PLS factors (R² -0,966 and RMSEP-6,84) for quetiapine, 8 PLS factors (R²-0,927 and RMSEP 6,84) for HPMC and 3 PLS factors (R²-0,983 and RMSEP-7,26) for microcrystalline cellulose. The methods were fully validated according to the ICH guidance using these calibration models. Regarding the trueness of the methods, the recovery was between 98.51 and 99.43 for quetiapine, between 98.61 and 100.85 for HPMC, and between 100.61 and 101.78 for microcrystalline cellulose. According to data obtained, the accuracy profile was ± 5 for quetiapine and HPMC, and ± 6 for microcrystalline cellulose. Linearity profile was also in establish intervals at accuracy and the R2 value was 0.983 for quetiapine, 0.948 for HPMC and 0.997 for microcrystalline cellulose. In conclusion, the developed NIR-chemometric methods have suitable reproducibility, accuracy, linearity and can be used for quantitative characterisation of extended-release tablets with quetiapine, with any sample preparation

    Cell fate specification and competence by Coco, a maternal BMP, TGFβand Wnt inhibitor

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    Patterning of the pre-gastrula embryo and subsequent neural induction post-gastrulation are very complex and intricate processes of which little, until recently, has been understood. The earliest decision in neural development, the choice between epidermal or neural fates, is regulated by bone morphogenetic protein (BMP) signaling within the ectoderm. Inhibition of BMP signaling is sufficient for neural induction. Many secreted BMP inhibitors are expressed exclusively within the organizer of the Xenopus gastrula embryo and therefore are predicted to act as bona fide endogenous neural inducers. Other cell-autonomous inhibitors of the BMP pathway are more widely expressed, such as the inhibitory Smads, Smad6 and Smad7. In this report we describe the biological and biochemical characterization of 51-B6, a novel member of Cerberus/Dan family of secreted BMP inhibitors, which we identified in a screen for Smad7-induced genes. This gene is expressed maternally in an animal to vegetal gradient, and its expression levels decline rapidly following gastrulation. In contrast to known BMP inhibitors, 51-B6 is broadly expressed in the ectoderm until the end of gastrulation. The timing, pattern of expression, and activities of this gene makes it unique when compared to other BMP/TGFbeta/Wnt secreted inhibitors which are expressed only zygotically and maintained post-gastrulation. We propose that a function of 51-B6 is to block BMP and TGFbeta signals in the ectoderm in order to regulate cell fate specification and competence prior to the onset of neural induction. In addition, we demonstrate that 51-B6 can act as a neural inducer and induce ectopic head-like structures in neurula staged embryos. Because of this embryological activity, we have renamed this clone Coco, after the Spanish word meaning head

    Birds of a feather eat plastic together: high levels of plastic ingestion in Great Shearwater adults and juveniles across their annual migratory cycle

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    © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Robuck, A. R., Hudak, C. A., Agvent, L., Emery, G., Ryan, P. G., Perold, V., Powers, K. D., Pedersen, J., Thompson, M. A., Suca, J. J., Moore, M. J., Harms, C. A., Bugoni, L., Shield, G., Glass, T., Wiley, D. N., & Lohmann, R. Birds of a feather eat plastic together: high levels of plastic ingestion in Great Shearwater adults and juveniles across their annual migratory cycle. Frontiers in Marine Science, 8, (2022): 719721, https://doi.org/10.3389/fmars.2021.719721.Limited work to date has examined plastic ingestion in highly migratory seabirds like Great Shearwaters (Ardenna gravis) across their entire migratory range. We examined 217 Great Shearwaters obtained from 2008–2019 at multiple locations spanning their yearly migration cycle across the Northwest and South Atlantic to assess accumulation of ingested plastic as well as trends over time and between locations. A total of 2328 plastic fragments were documented in the ventriculus portion of the gastrointestinal tract, with an average of 9 plastic fragments per bird. The mass, count, and frequency of plastic occurrence (FO) varied by location, with higher plastic burdens but lower FO in South Atlantic adults and chicks from the breeding colonies. No fragments of the same size or morphology were found in the primary forage fish prey, the Sand Lance (Ammodytes spp., n = 202) that supports Great Shearwaters in Massachusetts Bay, United States, suggesting the birds directly ingest the bulk of their plastic loads rather than accumulating via trophic transfer. Fourier-transform infrared spectroscopy indicated that low- and high-density polyethylene were the most common polymers ingested, within all years and locations. Individuals from the South Atlantic contained a higher proportion of larger plastic items and fragments compared to analogous life stages in the NW Atlantic, possibly due to increased use of remote, pelagic areas subject to reduced inputs of smaller, more diverse, and potentially less buoyant plastics found adjacent to coastal margins. Different signatures of polymer type, size, and category between similar life stages at different locations suggests rapid turnover of ingested plastics commensurate with migratory stage and location, though more empirical evidence is needed to ground-truth this hypothesis. This work is the first to comprehensively measure the accumulation of ingested plastics by Great Shearwaters over the last decade and across multiple locations spanning their yearly trans-equatorial migration cycle and underscores their utility as sentinels of plastic pollution in Atlantic ecosystems.This project was supported by the NOAA Fisheries National Seabird Program and the Volgenau Foundation. AR acknowledges support from the National Oceanic and Atmospheric Administration Dr. Nancy Foster Scholarship Program (NOAA Award Number NA17NOS4290028), the Robert and Patricia Switzer Foundation, the STEEP Superfund Research Program (NIEHS Award Number P42ES027706), and the Oak Ridge Institute for Science and Education (ORISE) program. LB was funded by INCT-Mar COI and PQ Grant No. 311409/2018-0, both by the Brazilian National Research Council (CNPq). JS was funded by the National Science Foundation Graduate Research Fellowship program

    Fluid flow and interlinked feedback loops establish left-right asymmetric decay of Cerl2 mRNA

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    Breaking of left-right symmetry in mouse embryos requires fluid flow at the node, but the precise action of the flow has remained unknown. Here we show that the left-right asymmetry of Cerl2 expression around the node, a target of the flow, is determined post-transcriptionally by decay of Cerl2 mRNA in a manner dependent on its 3' untranslated region. Cerl2 mRNA is absent specifically from the apical region of crown cells on the left side of the node. Preferential decay of Cerl2 mRNA on the left is initiated by the leftward flow and further enhanced by the operation of Wnt-Cerl2 interlinked feedback loops, in which Wnt3 upregulates Wnt3 expression and promotes Cerl2 mRNA decay, whereas Cerl2 promotes Wnt degradation. Mathematical modelling and experimental data suggest that these feedback loops behave as a bistable switch that can amplify in a noise-resistant manner a small bias conferred by fluid flow.Ministry of Education, Culture, Sports, Science, and Technology of Japan; Core Research for Evolutional Science and Technology (CREST) of the Japan Science and Technology Corporation (JST); GCOE of Osaka University; FCTinfo:eu-repo/semantics/publishedVersio

    Multivariate analysis as a method to understand variability in a complex excipient, and its contribution to formulation performance

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    A key part of the Risk Assessment of excipients is to understand how raw material variability could (or does) contribute to differences in performance of the drug product. Here we demonstrate an approach which achieves the necessary understanding for a complex, functional, excipient. Multivariate analysis (MVA) of the certificates of analysis of an ethylcellulose aqueous dispersion (Surelease) formulation revealed low overall variability of the properties of the systems. Review of the scores plot to highlight batches manufactured using the same ethylcellulose raw material in the formulation, indicated that these batches tend to be more closely related than other randomly selected batches. This variability could result in potential differences in the quality of drug product lots made from these batches. Manufacture of a model drug product from Surelease batches coated using different lots of starting material revealed small differences in the release of a model drug, which could be detected by certain model dependent dissolution modelling techniques, but they were not observed when using model-independent techniques. This illustrates that the techniques are suitable for detecting and understanding excipient variability, but that, in this case, the product was still robust
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