733 research outputs found

    A Herschel study of AGB stars in the Milky Way

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    The Asymptotic Giant Branch (AGB) stars are low to intermediate-mass post-MS stars that undergo thermal pulses characterized by a strong wind-driven mass loss from its surface into the interstellar medium. They are responsible for the majority of the dust contained within the Galactic plane and thus, their study is crucial to understand the life cycle of dust in our Galaxy. The Hi-GAL Survey constitutes the perfect survey to detect and study AGB stars since it uses the PACS and SPIRE Herschel instruments in parallel mode to map the |l|< 60°; |b| <1° region of the Galactic plane in the 70 ”m, 160 ”m, 250 ”m, 350 ”m and 500 ”m bands, which trace the emission of the dust in which AGB stars are embedded. In this thesis I use the Hi-GAL 1 maps processed with the ROMAGAL Pipeline to create a total of four catalogues: The SMA Hi-GAL 1 Point Source Catalogue - this is, to date, the most reliable Hi-GAL 1 PSC published. It contains the position and fluxes of all the Hi-GAL 1 compact sources detected by CUTEX in the 70 ”m Herschel band and the corresponding counterparts found in the other Herschel bands. The SMA Hi-GAL 1 PSC AGB star candidate catalogue - this is the first catalogue including a list of possible Hi-GAL 1 AGB star candidates. The source classification was done by means of colour cuts that efficiently separate 95 reference Hi-GAL 1 AGB stars from 205 reference YSOs, 178 HII regions and 59 PNe. This is, to date, the largest sample of reference Hi-GAL 1 sources used on colour-colour separation methods. These colour cuts involve the Herschel 70 ”m band and prove that this band plays a decisive role in identifying AGB stars and that it is highly effective in distinguishing AGB stars from other stellar types. The SMA Hi-GAL 1 PSC C-rich and O-rich AGB star candidate catalogues - these are the first two catalogues including a list of possible Hi-GAL 1 PSC C-rich and O-rich AGB star candidates and constitute the largest compilation of AGB stars detected within the Hi-GAL 1 Galactic region. The source classification was done by means of colour cuts that successfully separate 101 reference OH/IR-stars from 56 reference C-stars. These colour cuts involve the MSX 8.28 ”m band, the AKARI 9 ”m and 18 ”m bands and the WISE 12 ”m and 22 ”m bands, which cover the silicate and carbonaceous features of O-rich and C-rich AGB stars, and prove that these bands are highly efficient in distinguishing C-rich from O-rich AGB stars. The analysis of the stellar properties derived for the Hi-GAL 1 PSC C-rich and O-rich AGB star candidates allowed us to define a series of equations that establish the relation between the stars' mass-loss rates and their colour temperatures, NIR [J]-[K] colour, luminosities and outflow velocities. These equations are of great importance since they enable us to derive the mass-loss rates of unknown AGB stars using only their colour temperatures

    Using Machine Learning and Natural Language Processing to Review and Classify the Medical Literature on Cancer Susceptibility Genes

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    PURPOSE: The medical literature relevant to germline genetics is growing exponentially. Clinicians need tools monitoring and prioritizing the literature to understand the clinical implications of the pathogenic genetic variants. We developed and evaluated two machine learning models to classify abstracts as relevant to the penetrance (risk of cancer for germline mutation carriers) or prevalence of germline genetic mutations. METHODS: We conducted literature searches in PubMed and retrieved paper titles and abstracts to create an annotated dataset for training and evaluating the two machine learning classification models. Our first model is a support vector machine (SVM) which learns a linear decision rule based on the bag-of-ngrams representation of each title and abstract. Our second model is a convolutional neural network (CNN) which learns a complex nonlinear decision rule based on the raw title and abstract. We evaluated the performance of the two models on the classification of papers as relevant to penetrance or prevalence. RESULTS: For penetrance classification, we annotated 3740 paper titles and abstracts and used 60% for training the model, 20% for tuning the model, and 20% for evaluating the model. The SVM model achieves 89.53% accuracy (percentage of papers that were correctly classified) while the CNN model achieves 88.95 % accuracy. For prevalence classification, we annotated 3753 paper titles and abstracts. The SVM model achieves 89.14% accuracy while the CNN model achieves 89.13 % accuracy. CONCLUSION: Our models achieve high accuracy in classifying abstracts as relevant to penetrance or prevalence. By facilitating literature review, this tool could help clinicians and researchers keep abreast of the burgeoning knowledge of gene-cancer associations and keep the knowledge bases for clinical decision support tools up to date

    The Inclusion of Concentrate with Quebracho Is Advisable in Two Forage-Based Diets of Ewes According to the In Vitro Fermentation Parameters

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    Simple Summary In dry, mountainous areas, ewes are fed low-quality forages (hay or straw) indoors, although they also graze in high-quality pastures when available. Concentrate supplementation is recommended to cover high nutritional requirements during lactation. Condensed tannins (CT) of quebracho (Schinopsis balansae) can be included in the concentrate to reduce methane (CH4) emissions and ruminal degradation of protein, improving the fermentation’s efficiency. Furthermore, low levels of quebracho can improve some meat and milk quality traits. The effects of the inclusion of concentrate and CT in diets depend on the level of inclusion and the quality of forage. The aim of this study was to evaluate the in vitro fermentation characteristics of diets in order to identify the most suitable one to be fed to ewes under farming conditions. The diets examined differed in quality of the forage available, comparing hay versus fresh forage diets and forage alone versus 70:30 forage:concentrate with (quebracho) or without CT (control) in each type of forage. The fresh-forage-based diets had lower gas and CH4 production and greater in vitro organic matter degradability (IVOMD) than the hay-based diets. The inclusion of quebracho concentrate increased the IVOMD in hay-based diets and reduced ammonia content in fresh-forage-based diets. Abstract Ewes receive hay or graze on fresh pastures supplemented with concentrates to fulfil their lactation requirements. Quebracho (Schinopsis balansae) can be added to change the ruminal fermentation. Fermentation parameters of forages alone and 70:30 forage:concentrate diets with control and quebracho concentrate were compared after 24 h of in vitro incubation. Fresh forage diets produced less gas (p < 0.05) and had greater IVOMD (p < 0.001), ammonia (NH3-N) content, valeric acid, branched-chain volatile fatty acid proportions, and lower propionic acid proportion than the hay diets (p < 0.01). In the hay diets, methane production increased with control concentrate (p < 0.01) and tended to decrease with quebacho concentrate (p < 0.10). The inclusion of both concentrates increased the acetic:propionic ratio (p < 0.01), and only the inclusion of quebracho concentrate increased the IVOMD (p < 0.01). In the fresh forage diets, gas and methane production increased with the inclusion of the control concentrate (p < 0.05), but methane production decreased with quebracho concentrate (p < 0.01). The inclusion of quebracho concentrate reduced the NH3-N content and valeric acid proportion (p < 0.05). In conclusion, the inclusion of quebracho concentrate would be advisable to reduce the CH4 production and NH3-N content in fresh forage diets and to increase the IVOMD in hay diets in comparison with the forages alone

    Lipoma of the Uterine Corpus: Exceptional Eventuality Combined with an Ovarian Thecoma

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    Uterine lipomas are very uncommon with symptoms that are similar to leiomyomas. Their diagnosis is always histological although some radiological methods may suggest their existence prior to surgery. They are sometimes associated with endometrial pathology, but there are no previous reported cases related to ovarian thecoma. Their prognosis is excellent. Clinical, radiological, morphologic, and immunohistochemical findings are shown which correspond to uterine lipoma associated with endometrial polyps and ovarian thecoma

    Structural Diversity and Biological Potential of Alkaloids from the Genus Hippeastrum, Amaryllidaceae: an Update

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    The subfamily Amaryllidoideae, Amaryllidaceae, presents an exclusive group of structures known as Amaryllidaceae alkaloids, which have a broad spectrum of biological activities. These plants are classified into 59 genera, including Hippeastrum Herb., which comprises approximately 60 species distributed mainly in South America, being widely used as ornamental plants due to the beauty of its flowers. This review presents an update about the alkaloid profiling of Hippeastrum extracts published between 2012 and 2021, as well as an approach to the biological potential of these compounds. Supplementary information: The online version contains supplementary material available at 10.1007/s43450-021-00211-z. Keywords: Alzheimer's disease; Anti-inflammatory; Antiparasitic; Antitumoral; Cytotoxic; Isoquinoline alkaloids

    Identification of Alkaloids from Hippeastrum aulicum (Ker Gawl.) Herb.(Amaryllidaceae) Using CGC-MS and Ambient Ionization Mass Spectrometry (PS-MS and LS-MS)

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    Amaryllidaceae alkaloids are well-known isoquinolines which have demonstrated a wide range of biological activities such as antiviral, anticancer, acetylcholinesterase inhibition, antimalarial, among others. Mass spectrometry (MS) studies based on capillary gas chromatography (CGC), paper spray (PS), and leaf spray (LS) ionization were carried out for alkaloid investigation of the native Brazilian species Hippeastrum aulicum, along with nuclear magnetic resonance (NMR) techniques. Thirty-one alkaloids were identified including the new compound haemanthamine N-oxide. The results from PS- and LS-MS techniques were consistent with those observed in CGC-MS analysis. To the best of our knowledge, it is the first study combining NMR, CGC-MS and the ambient ionization-mass spectrometry (PS- and LS-MS) on Amaryllidaceae plants

    The Case for Quantum Key Distribution

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    Quantum key distribution (QKD) promises secure key agreement by using quantum mechanical systems. We argue that QKD will be an important part of future cryptographic infrastructures. It can provide long-term confidentiality for encrypted information without reliance on computational assumptions. Although QKD still requires authentication to prevent man-in-the-middle attacks, it can make use of either information-theoretically secure symmetric key authentication or computationally secure public key authentication: even when using public key authentication, we argue that QKD still offers stronger security than classical key agreement.Comment: 12 pages, 1 figure; to appear in proceedings of QuantumComm 2009 Workshop on Quantum and Classical Information Security; version 2 minor content revision

    ACUOS: A System for Modular ACU Generalization with Subtyping and Inheritance

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    The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-11558-0_40Computing generalizers is relevant in a wide spectrum of automated reasoning areas where analogical reasoning and inductive inference are needed. The ACUOS system computes a complete and minimal set of semantic generalizers (also called “anti-unifiers”) of two structures in a typed language modulo a set of equational axioms. By supporting types and any (modular) combination of associativity (A), commutativity (C), and unity (U) algebraic axioms for function symbols, ACUOS allows reasoning about typed data structures, e.g. lists, trees, and (multi-)sets, and typical hierarchical/structural relations such as is a and part of. This paper discusses the modular ACU generalization tool ACUOS and illustrates its use in a classical artificial intelligence problem.This work has been partially supported by the EU (FEDER) and the Spanish MINECO under grants TIN 2010-21062-C02-02 and TIN 2013-45732-C4-1-P, by Generalitat Valenciana PROMETEO2011/052, and by NSF Grant CNS 13-10109. J. Espert has also been supported by the Spanish FPU grant FPU12/06223.Alpuente Frasnedo, M.; Escobar RomĂĄn, S.; Espert Real, J.; Meseguer, J. (2014). ACUOS: A System for Modular ACU Generalization with Subtyping and Inheritance. En Logics in Artificial Intelligence. Springer. 573-581. https://doi.org/10.1007/978-3-319-11558-0_40S573581Alpuente, M., Escobar, S., Espert, J., Meseguer, J.: A Modular Order-sorted Equational Generalization Algorithm. Information and Computation 235, 98–136 (2014)Alpuente, M., Escobar, S., Meseguer, J., Ojeda, P.: A Modular Equational Generalization Algorithm. In: Hanus, M. (ed.) LOPSTR 2008. LNCS, vol. 5438, pp. 24–39. Springer, Heidelberg (2009)Alpuente, M., Escobar, S., Meseguer, J., Ojeda, P.: Order–Sorted Generalization. ENTCS 246, 27–38 (2009)Alpuente, M., Espert, J., Escobar, S., Meseguer, J.: ACUOS: A System for Modular ACU Generalization with Subtyping and Inheritance. Tech. rep., DSIC-UPV (2013), http://www.dsic.upv.es/users/elp/papers.htmlArmengol, E.: Usages of Generalization in Case-Based Reasoning. In: Weber, R.O., Richter, M.M. (eds.) ICCBR 2007. LNCS (LNAI), vol. 4626, pp. 31–45. Springer, Heidelberg (2007)Clavel, M., DurĂĄn, F., Eker, S., Lincoln, P., MartĂ­-Oliet, N., Meseguer, J., Talcott, C. (eds.): All About Maude - A High-Performance Logical Framework. LNCS, vol. 4350. Springer, Heidelberg (2007)Clavel, M., DurĂĄn, F., Eker, S., Lincoln, P., MartĂ­-Oliet, N., Meseguer, J., Talcott, C.L.: Reflection, metalevel computation, and strategies. In: All About Maude [6], pp. 419–458Gentner, D.: Structure-Mapping: A Theoretical Framework for Analogy*. Cognitive Science 7(2), 155–170 (1983)Krumnack, U., Schwering, A., Gust, H., KĂŒhnberger, K.-U.: Restricted higher order anti unification for analogy making. In: Orgun, M.A., Thornton, J. (eds.) AI 2007. LNCS (LNAI), vol. 4830, pp. 273–282. Springer, Heidelberg (2007)Kutsia, T., Levy, J., Villaret, M.: Anti-Unification for Unranked Terms and Hedges. Journal of Automated Reasoning 520, 155–190 (2014)Meseguer, J.: Conditioned rewriting logic as a united model of concurrency. Theor. Comput. Sci. 96(1), 73–155 (1992)Muggleton, S.: Inductive Logic Programming: Issues, Results and the Challenge of Learning Language in Logic. Artif. Intell. 114(1-2), 283–296 (1999)Ontañón, S., Plaza, E.: Similarity measures over refinement graphs. Machine Learning 87(1), 57–92 (2012)Plotkin, G.: A note on inductive generalization. In: Machine Intelligence, vol. 5, pp. 153–163. Edinburgh University Press (1970)Pottier, L.: Generalisation de termes en theorie equationelle: Cas associatif-commutatif. Tech. Rep. INRIA 1056, Norwegian Computing Center (1989)Schmid, U., Hofmann, M., Bader, F., HĂ€berle, T., Schneider, T.: Incident Mining using Structural Prototypes. In: GarcĂ­a-Pedrajas, N., Herrera, F., Fyfe, C., BenĂ­tez, J.M., Ali, M. (eds.) IEA/AIE 2010, Part II. LNCS, vol. 6097, pp. 327–336. Springer, Heidelberg (2010
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