Browsing by Author "Reyes, E."

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    Alert Classification for the ALeRCE Broker System: The Real-time Stamp Classifier
    (2021) Carrasco-Davis, R.; Reyes, E.; Valenzuela, C.; Förster, F.; Estévez, P. A.; Pignata, G.; Bauer, F. E.; Reyes, I.; Sánchez-Sáez, P.; Cabrera-Vives, G.; Eyheramendy, S.; Catelan, Márcio; Arredondo, J.; Castillo-Navarrete, E.; Rodríguez-Mancini, D.; Ruz-Mieres, D.; Moya, A.; Sabatini-Gacitúa, L.; Sepúlveda-Cobo, C.; Mahabal, A. A.; Silva-Farfán, J.; Camacho-Iñiguez, E.; Galbany, L.
    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....
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    Open label, prospective, randomized controlled trial of an endoscopic duodenal-jejunal bypass sleeve versus low calorie diet for pre-operative weight loss in bariatric surgery
    (2009) Tarnoff, M.; Rodriguez, L.; Escalona, A.; Ramos, A.; Neto, M.; Alamo, M.; Reyes, E.; Pimentel, F.; Ibanez, L.
    The duodenal-jejunal bypass sleeve (DJBS) has been shown to achieve a completely endoscopic duodenal exclusion without the need for stapling. This report is the first randomized controlled trial for weight loss.
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    Redefining micrometastasis in prostate cancer - a comparison of circulating prostate cells, bone marrow disseminated tumor cells and micrometastasis: Implications in determining local or systemic treatment for biochemical failure after radical prostatectomy
    (2012) Murray, N. P.; Reyes, E.; Tapia, P.; Badinez, L.; Orellana, N.; Fuentealba, C.; Olivares, R.; Porcell, J.; Duenas, R.
    The presence of cells positive for cytokeratins or prostate-specific antigen (PSA) in bone marrow aspirates (BMAs) has been used to indicate the presence of micrometastasis. The aim of this prospective study of prostate cancer patients was to determine the presence of prostate cells in blood and BMAs and to compare them with bone marrow biopsy touch prep samples. The results indicated that there was a satisfactory concordance between circulating prostate cells (CPCs) in blood and disseminated tumor cells (DTCs) in BMAs for all Gleason scores (kappa>0.50). However, neither were concordant with the presence of prostate cells in bone marrow biopsies except for high-grade tumors, Gleason 8 and 9. Phenotypic characteristics of CPCs and DTCs were identical (kappa>0.9) but were different than cells detected in bone marrow biopsies (kappa<0.2). The expression of matrix metalloproteinase-2 (MMP-2) in bone marrow biopsies was positively associated with the Gleason score (trend Chi-squared <0.05) and may explain the differences between the presence of DTCs and the presence of prostate cells in bone marrow biopsies. If the presence of DTCs was used to indicate micrometastatic disease, 20% of patients would be misclassified compared to micrometastasis defined as patients with a positive biopsy. This may have clinical implications for patients with low-grade tumors.
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    Transient Classification Report for 2020-12-01
    (2020) Dodin, A.; Tsvetkov, D.; Shatski, N.; Belinski, A.; Galbany, L.; Munoz-Arancibia, A.; Forster, F.; Bauer, F. E.; Hernandez-Garcia, L.; Pignata, G.; Camacho, E.; Silva-Farfan, J.; Mourao, A.; Arredondo, J.; Cabrera-Vives, G.; Carrasco-Davis, R.; Estevez, P. A.; Huijse, P.; Reyes, E.; Reyes, I.; Sanchez-Saez, P.; Valenzuela, C.; Castillo, E.; Ruz-Mieres, D.; Rodriguez-Mancini, D.; Catelan, Marcio; Eyheramendy, S.; Graham, M. J.
    F. Forster, F.E. Bauer, G. Pignata, J. Arredondo, G. Cabrera-Vives, R. Carrasco-Davis, P.A. Estevez, P. Huijse, E. Reyes, I. Reyes, P. Sanchez-Saez, C. Valenzuela, E. Castillo, D. Ruz-Mieres, D. Rodriguez-Mancini, F.E. Bauer, M. Catelan, S. Eyheramendy, M.J. Graham on behalf of the ALeRCE broker report/s the discovery of a new astronomical transient.