46 research outputs found
Alert classification for the ALeRCE broker system: The real-time stamp classifier
We present a real-time stamp classifier of astronomical events for the Automatic Learning for the Rapid Classification of Events broker, ALeRCE. The classifier is based on a convolutional neural network, trained on alerts ingested from the Zwicky Transient Facility (ZTF). Using only the science, reference, and difference images of the first detection as inputs, along with the metadata of the alert as features, the classifier is able to correctly classify alerts from active galactic nuclei, supernovae (SNe), variable stars, asteroids, and bogus classes, with high accuracy (~94%) in a balanced test set. In order to find and analyze SN candidates selected by our classifier from the ZTF alert stream, we designed and deployed a visualization tool called SN Hunter, where relevant information about each possible SN is displayed for the experts to choose among candidates to report to the Transient Name Server database. From 2019 June 26 to 2021 February 28, we have reported 6846 SN candidates to date (11.8 candidates per day on average), of which 971 have been confirmed spectroscopically. Our ability to report objects using only a single detection means that 70% of the reported SNe occurred within one day after the first detection. ALeRCE has only reported candidates not otherwise detected or selected by other groups, therefore adding new early transients to the bulk of objects available for early follow-up. Our work represents an important milestone toward rapid alert classifications with the next generation of large etendue telescopes, such as the Vera C. Rubin Observatory.The authors acknowledge support from the National Agency
of Research and Development’s Millennium Science Initiative
through grant IC12009, awarded to the Millennium Institute of
Astrophysics (RC, ER, CV, FF, PE, GP, FEB, IR, PSS, GC,
SE, Ja, EC, DR, DRM, MC) and from the National Agency for
Research and Development (ANID) grants: BASAL Center of
Mathematical Modelling AFB-170001 (CV, FF, IR, ECN, CS,
ECI) and Centro de Astrofísica y Tecnologías Afines AFB170002 (FEB, PSS, MC); FONDECYT Regular #1171678
(PE), #1200710 (FF), #1190818(FEB), #1200495 (FEB),
#1171273 (MC), #1201793(GP); FONDECYT Postdoctorado
#3200250 (PSS); FONDECYT Iniciación #11191130 (CV);
Magíster Nacional 2019 #22190947 (ER). This work was
funded in part by project CORFO 10CEII-9157 Inria Chile
(PS). The authors acknowledge financial support from the
Spanish Ministry of Science, Innovation, and Universities
(MICIU) under the 2019 Ramón y Cajal program RYC2019-
027683 (LG)
ATP7A is a novel target of retinoic acid receptor β2 in neuroblastoma cells
Increased retinoic acid receptor β (RARβ2) gene expression is a hallmark of cancer cell responsiveness to retinoid anticancer effects. Moreover, low basal or induced RARβ2 expression is a common feature of many human cancers, suggesting that RARβ2 may act as a tumour suppressor gene in the absence of supplemented retinoid. We have previously shown that low RARβ2 expression is a feature of advanced neuroblastoma. Here, we demonstrate that the ABC domain of the RARβ2 protein alone was sufficient for the growth inhibitory effects of RARβ2 on neuroblastoma cells. ATP7A, the copper efflux pump, is a retinoid-responsive gene, was upregulated by ectopic overexpression of RARβ2. The ectopic overexpression of the RARβ2 ABC domain was sufficient to induce ATP7A expression, whereas, RARβ2 siRNA blocked the induction of ATP7A expression in retinoid-treated neuroblastoma cells. Forced downregulation of ATP7A reduced copper efflux and increased viability of retinoid-treated neuroblastoma cells. Copper supplementation enhanced cell growth and reduced retinoid-responsiveness, whereas copper chelation reduced the viability and proliferative capacity. Taken together, our data demonstrates ATP7A expression is regulated by retinoic acid receptor β and it has effects on intracellular copper levels, revealing a link between the anticancer action of retinoids and copper metabolism
She\u27s So Bubbly
We introduce the Automatic Learning for the Rapid Classification of Events (ALeRCE) broker, an astronomical alert broker designed to provide a rapid and self-consistent classification of large etendue telescope alert streams, such as that provided by the Zwicky Transient Facility (ZTF) and, in the future, the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). ALeRCE is a Chilean-led broker run by an interdisciplinary team of astronomers and engineers working to become intermediaries between survey and follow-up facilities. ALeRCE uses a pipeline that includes the real-time ingestion, aggregation, cross-matching, machine-learning (ML) classification, and visualization of the ZTF alert stream. We use two classifiers: a stamp-based classifier, designed for rapid classification, and a light curve–based classifier, which uses the multiband flux evolution to achieve a more refined classification. We describe in detail our pipeline, data products, tools, and services, which are made public for the community (see https://alerce.science). Since we began operating our real-time ML classification of the ZTF alert stream in early 2019, we have grown a large community of active users around the globe. We describe our results to date, including the real-time processing of 1.5 × 10⁸ alerts, the stamp classification of 3.4 × 10⁷ objects, the light-curve classification of 1.1 × 10⁶ objects, the report of 6162 supernova candidates, and different experiments using LSST-like alert streams. Finally, we discuss the challenges ahead in going from a single stream of alerts such as ZTF to a multistream ecosystem dominated by LSST
Effect of the COVID-19 pandemic on surgery for indeterminate thyroid nodules (THYCOVID): a retrospective, international, multicentre, cross-sectional study
Background Since its outbreak in early 2020, the COVID-19 pandemic has diverted resources from non-urgent and elective procedures, leading to diagnosis and treatment delays, with an increased number of neoplasms at advanced stages worldwide. The aims of this study were to quantify the reduction in surgical activity for indeterminate thyroid nodules during the COVID-19 pandemic; and to evaluate whether delays in surgery led to an increased occurrence of aggressive tumours.Methods In this retrospective, international, cross-sectional study, centres were invited to participate in June 22, 2022; each centre joining the study was asked to provide data from medical records on all surgical thyroidectomies consecutively performed from Jan 1, 2019, to Dec 31, 2021. Patients with indeterminate thyroid nodules were divided into three groups according to when they underwent surgery: from Jan 1, 2019, to Feb 29, 2020 (global prepandemic phase), from March 1, 2020, to May 31, 2021 (pandemic escalation phase), and from June 1 to Dec 31, 2021 (pandemic decrease phase). The main outcomes were, for each phase, the number of surgeries for indeterminate thyroid nodules, and in patients with a postoperative diagnosis of thyroid cancers, the occurrence of tumours larger than 10 mm, extrathyroidal extension, lymph node metastases, vascular invasion, distant metastases, and tumours at high risk of structural disease recurrence. Univariate analysis was used to compare the probability of aggressive thyroid features between the first and third study phases. The study was registered on ClinicalTrials.gov, NCT05178186.Findings Data from 157 centres (n=49 countries) on 87 467 patients who underwent surgery for benign and malignant thyroid disease were collected, of whom 22 974 patients (18 052 [78 center dot 6%] female patients and 4922 [21 center dot 4%] male patients) received surgery for indeterminate thyroid nodules. We observed a significant reduction in surgery for indeterminate thyroid nodules during the pandemic escalation phase (median monthly surgeries per centre, 1 center dot 4 [IQR 0 center dot 6-3 center dot 4]) compared with the prepandemic phase (2 center dot 0 [0 center dot 9-3 center dot 7]; p<0 center dot 0001) and pandemic decrease phase (2 center dot 3 [1 center dot 0-5 center dot 0]; p<0 center dot 0001). Compared with the prepandemic phase, in the pandemic decrease phase we observed an increased occurrence of thyroid tumours larger than 10 mm (2554 [69 center dot 0%] of 3704 vs 1515 [71 center dot 5%] of 2119; OR 1 center dot 1 [95% CI 1 center dot 0-1 center dot 3]; p=0 center dot 042), lymph node metastases (343 [9 center dot 3%] vs 264 [12 center dot 5%]; OR 1 center dot 4 [1 center dot 2-1 center dot 7]; p=0 center dot 0001), and tumours at high risk of structural disease recurrence (203 [5 center dot 7%] of 3584 vs 155 [7 center dot 7%] of 2006; OR 1 center dot 4 [1 center dot 1-1 center dot 7]; p=0 center dot 0039).Interpretation Our study suggests that the reduction in surgical activity for indeterminate thyroid nodules during the COVID-19 pandemic period could have led to an increased occurrence of aggressive thyroid tumours. However, other compelling hypotheses, including increased selection of patients with aggressive malignancies during this period, should be considered. We suggest that surgery for indeterminate thyroid nodules should no longer be postponed even in future instances of pandemic escalation.Funding None.Copyright (c) 2023 Published by Elsevier Ltd. All rights reserved
Dysregulated cholinergic network as a novel biomarker of poor prognostic in patients with head and neck squamous cell carcinoma
Effect of the Initial Stocking Body Weigth on Growth of Spotted Rose Snapper Lutjanus Guttatus (Steindachner, 1869) in Marine Floting Cages
Pargos lunarejos con pesos promedio de 24,5 ± 3,7 g, 55,4 ± 3,5 g y 110,2 ± 4,6 g fueron introducidos para su engorde en jaulas flotantes de 100 m3 por un lapso de 153 días en Santa Cruz de Miramar, Nayarit, México, con la finalidad de encontrar el peso más adecuado de cultivo. Los pargos fueron alimentados dos veces al día con alimento comercial conteniendo 35 y 25% de proteína cruda durante el primero a tercer mes y en el cuarto y quinto mes respectivamente. Durante el experimento, la temperatura del agua varió de 25,6 a 32,3ºC. Al final del experimento se obtuvo una supervivencia que fluctuó de 67,5 a 74,7%. Se determinaron, con base en el peso inicial, diferencias estadísticamente significativas (P&#8804;0,05) con respecto a la biomasa final cosechada. La máxima ganancia en peso promedio semanal fue de 12,8 g semana-1 en los organismos con el mayor peso inicial (110,2 ± 4,6 g). Esta información sugiere que la inclusión de pargos lunarejos con un peso de 110 g puede ser una buena estrategia para el engorde en jaulas flotantes
El balance hídrico en el municipio de La Yesca, Nayarit, México
The purpose of this study was to calculate the water balance components in La Yesca municipality, Nayarit, Mexico. Methodology was used to obtain the water balance components in surface river basins, where the choice and application of algorithms to determine the volumes of water that do not have gauging depend on the type of statistical and geographical information available. The results of the estimates of water balance components in La Yesca municipality show that a water volume of about 114. 856 m3 s-1 is precipitated, from it the 88 % (101.141 m3 s-1) evapotranspires, a lower portion recharges the underlying aquifers (3.019 m3 s-1) and the rest runs off at about 10,696 m3 s-1; from these runoffs, approximately 0.026 m3 s-1 is used mainly for public use. Therefore we can say that the most important source of water supply of La Yesca municipality is formed by the flows of superficial water exploitation. In addition, there is an order import of 118.099 m3 s-1 coming from the Santiago and Bolaños Rivers. The annual extraction of groundwater belongs to order 0.004 m3 s-1. In the basin, 0.030 m3 s-1 of water are used, from which 0.026 m3 s-1 correspond to volumes of public use; the rest (0.004 m3 s-1) are used in agriculture and aquaculture.La finalidad del presente trabajo fue calcular las componentes del balance hídrico en el municipio de La Yesca, Nayarit, México. Se utilizó una metodología para obtener las componentes del balance hídrico en cuencas hidrográficas superficiales, donde la elección y aplicación de los algoritmos para determinar los volúmenes de agua que no cuentan con aforos dependen del tipo de información estadística y geográfica disponible. Los resultados de las estimaciones de las componentes del balance hídrico en el municipio de La Yesca, muestran que se precipita un volumen de agua del orden de 114.856 m3 s-1, de éste, se evapotranspira el 88 % (101.141 m3 s-1), una porción menor recarga el acuífero subyacente (3.019 m3 s-1) y el resto escurre superficialmente en alrededor de 10.696 m3 s-1; de estos escurrimientos se aprovecha aproximadamente 0.026 m3 s-1 para su uso público principalmente. Por esto se puede decir que la fuente más importante de abastecimiento de agua del municipio de La Yesca, la constituye los caudales de los aprovechamientos de agua superficial. Además de que se cuenta con una importación del orden de 118.099 m3 s-1 provenientes de los ríos Santiago y Bolaños. La extracción anual de agua subterránea es del orden de 0.004 m3 s-1. En la cuenca se utilizan 0.030 m3 s-1 de agua, de los cuales 0.026 m3 s-1 corresponden a volúmenes de uso público; el resto (0.004 m3 s-1) son de uso agrícola y acuícola