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The standard treatment for newly diagnosed glioblastoma includes maximal safe surgical resection followed by concurrent radiation therapy and temozolomide (TMZ) and maintenance TMZ. The impact of time to start radiation therapy (TRT) on overall survival (OS) in glioblastoma patients is controversial. The study aimed to evaluate the impact of TRT on OS in patients diagnosed with glioblastoma who received standard treatment. In this retrospective study, we included patients with confirmed diagnosis of glioblastoma treated from 2011 to 2016. TRT was defined as the time between surgery (biopsy or resection) and the first day of radiation therapy. The endpoint was OS. The patients were divided according to the TRT in three categories

BackgroundTo date, there are no comprehensive data on pediatric COVID-19 from Latin America. This study aims to assess COVID-19 and Multisystem Inflammatory Syndrome (MIS-C) in Latin American children, in order to appropriately plan and allocate resources to face the pandemic on a local and International leverMethodsAmbispective multicentre cohort study from five Latin American countries. Children aged 18 years or younger with microbiologically confirmed SARS-CoV-2 infection were included.Findings409 children were included, with a median age of 53.0 years (IQR 0.6–9.0). Of these, 95 191 (23.2%) were diagnosed with MIS-C. 191 (46.7%) children were admitted to hospital and 52 (12.7%) required admission to a Pediatric Intensive Care Unite (PICU). 92 (22.5%) patients required oxygen support: 8 (2%) were started on continuous positive airway pressure (CPAP) and 29 (7%) on mechanical ventilation. 35 (8.5%) patients required inotropic support. The following factors were associated with PICU admission: pre-existing medical condition (P < 0.0001), immunodeficiency (P = 0.01), lower respiratory tract infection (P< 0.0001), gastrointestinal symptoms (P = 0.006), radiological changes suggestive of pneumonia and acute respiratory distress syndrome (P< 0.0001), low socioeconomic conditions (P 0.009).ConclusionsThis study shows a generally more severe form of COVID-19 and a high number of MIS-C in Latin American children, compared with studies from China, Europe and North America, and support current evidence of a more severe disease in Latin/Hyspanic children or in people of lower socioeconomic level. The findings highlight an urgent need of more data of COVID-19 in South America.

Systemic inflammation plays a crucial role in carcinogenesis and progression of pancreatic cancer, due to its influence on tumor angiogenesis, invasion and metastasis. The association of CA 19-9, neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) can identify patients with different prognoses.We reviewed 148 pancreatic cancer patients' charts diagnosed from January 2006 to December 2018 in a tertiary hospital. Cox proportional survival models were used to evaluate the impact of each factor on recurrence-free and overall survival (OS).When assessing risk of relapse, the presence of angiolymphatic invasion was associated with an 80% chance of recurrence in 5 years. Among other factors associated with OS, the estimated risk of death in patients with CA 19-9300 U/mL was 2.37-fold higher compared to lower values. In addition, the risk of death was 60% and 76% higher in patients with NLR3 and PLR150, respectively. Patients within these 3 categories had a median OS of only 7.5 months, lower than all-comer patients with stage IV disease, with median OS estimated at 9.84 months.The laboratory variables CA 19-9, NLR and PLR together can contribute to a better stratification of patients with pancreatic adenocarcinoma beyond conventional staging. Prospective initiatives using these factors together can demonstrate different subgroups of patients who benefit from new treatment strategies.

FLOT regimen became the standard perioperative treatment in several centers around the world for esophagogastric tumors despite concerns about toxicity. In addition, FLOT has never been compared with other docetaxel-based regimens. To address this question, we conducted a systematic review of PubMed, Embase and Web of Science including prospective or retrospective studies of docetaxel based perioperative regimen in gastric and esophagogastric tumors. Data regarding chemotherapy regimens, efficacy and toxicity were extracted. Outcomes were compared using a random effects model. Of 548 abstracts, 16 were considered eligible. Comparing the studies with meta-analysis we can see that the regimens are similar in terms of pathological complete response, resection rate, progression free survival and overall survival in one year, without significant heterogeneity. The meta-regression of docetaxel dose failed to show any association with dose ranging between 120–450 mg/m². Regarding the toxicity of the regimens it is noted that the regimens are quite toxic (up to 50–70% of grade 3–4 neutropenia). The results of this meta-analysis with a combined sample size of more than 1,000 patients suggest that docetaxel perioperative regimens are equivalent in outcomes. Prospective trials addressing modified regimens should be performed to provide less toxic strategies and be applicable to all patients.

Adaptive Optics (AO) systems aim at detecting and correcting for optical distortions induced by atmospheric turbulences. The Gemini Multi Conjugated AO System GeMS is operational and regularly used for science observations since 2013 delivering close to diffraction limit resolution over a large field of view. GeMS entered this year into a new era. The laser system has been upgraded from the old 50W Lockheed Martin Coherent Technologies (LMCT) pulsed laser to the Toptica 20/2W CW SodiumStar laser. The laser has been successfully commissioned and is now used regularly in operation. In this paper we first review the performance obtained with the instrument. I will go then into the details of the commissioning of the Toptica laser and show the improvements obtained in term of acquisition, stability, reliability and performance.

Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States of America), The National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Minist´erio de Ciˆencia, Tecnologia e Inova¸c˜ao (Brazil) and Ministerio de Ciencia, Tecnologia e Innovaci´on Productiva (Argentina).

The Gemini Multi-conjugate Adaptive Optics System - GeMS, a facility instrument mounted on the Gemini South telescope, delivers a uniform, near diffraction limited images at near infrared wavelengths (0.95 microns- 2.5 microns) over a field of view of 120 arc seconds. GeMS is the first sodium layer based multi laser guide star adaptive optics system used in astronomy. It uses five laser guide stars distributed on a 60 arc seconds square constellation to measure for atmospheric distortions and two deformable mirrors to compensate for it. In this paper, the second devoted to describe the GeMS project, we present the commissioning, overall performance and operational scheme of GeMS. Performance of each sub-system is derived from the commissioning results. The typical image quality, expressed in full with half maximum, Strehl ratios and variations over the field delivered by the system are then described. A discussion of the main contributor to performance limitation is carried-out. Finally, overheads and future system upgrades are described., 20 pages, 11 figures, accepted for publication in MNRAS

International audience; AO systems aim at detecting and correcting for optical distortions induced by atmospheric turbulences. They are also extremely sensitive to extraneous sources of perturbation such as vibrations, which degrade the performance. The Gemini South telescope has currently two main AO systems: the Gemini Multi Conjugated AO System GeMS and the Gemini Planet Imager GPI. GeMS is operational and regularly used for science observation delivering close to diffraction limit resolution over a large field of view (85×85 arcsec2). Performance limitation due to the use of an integrator for tip-tilt control is here explored. In particular, this type of controller does not allow for the mitigation of vibrations with an arbitrary natural frequency. We have thus implemented a tip-tilt Linear Quadratic Gaussian (LQG) controller with different underlying perturbation models: (i) a sum of autoregressive models of order 2 identified from an estimated power spectrum density (s-AR2) of the perturbation,1 already tested on CANARY2 and routinely used on SPHERE;3 (ii) cascaded ARMA models of order 2 identified using prediction error minimization (c-PEM) as proposed in.4, 5 Both s-AR2 and c-PEM were parameterized to produce tip or tilt state-space models up to order 20 and 30 respectively. We discuss the parallelized implementation in the real time computer and the expected performance. On-sky tests are scheduled during the November 2016 run or the January 2017 run.

GeMS, the Gemini South MCAO System, has now been in operation for 3 years with the near infrared imager GSAOI. We first review the performance obtained by the system, the science cases and the current operational model. In the very near future, GeMS will undergo a profound metamorphosis, as we will integrate a new NGS wavefront sensor, replace the current 50W laser with a more robust one and prepare for a new operational model where operations will shift from the mountain to the base facility. Along this major evolution, we are also presenting several improvements on the loop control, calibrations and automatization of this complex system. We discuss here the progress of the different upgrades and what we expect in terms of performance improvements and operational efficiency.

NGS2 is an upgrade for the multi-natural guide star tip-tilt & plate scale wavefront sensor for GeMS (Gemini Multi-Conjugate Adaptive Optics system). It uses a single Nuvu HNu-512 Electron-Multiplied CCD array that spans the entire GeMS wavefront sensor focal plane. Multiple small regions-of-interest are used to enable frame rates up to 800Hz. This set up will improve the optical throughput with respect to the current wavefront sensor, as well as streamline acquisition and allow for distortion compensation.

Both Gemini telescopes, in Hawaii and Chile, are located in highly seismic active areas. That means that the seismic protection is included in the structural design of the telescope, instruments and auxiliary structure. We will describe the specific design features to reduce permanent damage in case of major earthquakes. At this moment both telescopes have been affected by big earthquakes in 2006 and 2015 respectively. There is an opportunity to compare the original design to the effects that are caused by these earthquakes and analyze their effectiveness. The paper describes the way the telescopes responded to these events, the damage that was caused, how we recovered from it, the modifications we have done to avoid some of this damage in future occasions, and lessons learned to face this type of events. Finally we will cover on how we pretend to upgrade the limited monitoring tools we currently have in place to measure the impact of earthquakes.

e21676 Background: Malignant obstruction (MO) is a common complication in patients with gastric cancer. Although palliative chemotherapy has already shown beneficial for overall survival in advanced cases, its value for MO reversal is still unknown. Methods: Inthis retrospective study we analyzed all consecutive patients with metastatic gastric cancer admitted with MO at the Instituto do Câncer do Estado de São Paulo (ICESP) from 2008 to 2016. The primary and secondary endpoints were overall survival and obstruction reversal rate respectively. Clinical measures other than chemotherapy and alimentary pause included the use of octreotide 0.1 mg, 3 times a day, steroids, antiemetics and anticholinergic drugs. Survival curves were calculated by Kaplan-Meier and log-rank test was used to compare them. The Cox regression model was used to evaluate risk factors for overall survival and the hazard ratio (HR) was calculated with its respective 95% confidence intervals. The analysis was performed in SPSS v.18 for Windows statistical software, and the significance level was 5%. Results: One hundred and eighteen(118)patients were included. Median overall survival was 11.2 months and survival time after the MO was 3.6 months for the whole group. Median time of use of octreotide was 3 days. Reversal of obstruction was seen in 16 of 36 patients (38.4%) in which chemotherapy was used and only in 22 of the 92 patients (24%) treated with exclusive clinical measures. In spite of these figures a significant better overall survival (p 0.002) was achieved in the group of patients that reached obstruction reversal without chemotherapy (13.6 months vs. 11.6 months for the clinical treatment group). Conclusions: This study suggests that chemotherapy even when reversing MO, has no impact in patients overall survival. These finding is particularly relevant for cost contingency in settings with limited resources. .

The Gemini Multi-conjugate adaptive optics System (GeMS) at the Gemini South telescope in Cerro Pachon is the first sodium Laser Guide Star (LGS) adaptive optics (AO) system with multiple guide stars. It uses five LGSs and two deformable mirrors (DMs) to measure and compensate for distortions induced by atmospheric turbulence. After its 2012 commissioning phase, it is now transitioning into regular operations. Although GeMS has unique scientific capabilities, it remains a challenging instrument to maintain, operate and upgrade. In this paper, we summarize the latest news and results. First, we describe the engineering work done this past year, mostly during our last instrument shutdown in 2013 austral winter, covering many subsystems: an erroneous reconjugation of the Laser guide star wavefront sensor, the correction of focus field distortion for the natural guide star wavefront sensor and engineering changes dealing with our laser and its beam transfer optics. We also describe our revamped software, developed to integrate the instrument into the Gemini operational model, and the new optimization procedures aiming to reduce GeMS time overheads. Significant software improvements were achieved on the acquisition of natural guide stars by our natural guide star wavefront sensor, on the automation of tip-tilt and higher-order loop optimization, and on the tomographic non-common path aberration compensation. We then go through the current operational scheme and present the plan for the next years. We offered 38 nights in our last semester. We review the current system efficiency in term of raw performance, completed programs and time overheads. We also present our current efforts to merge GeMS into the Gemini base facility project, where night operations are all reliably driven from our La Serena headquarter, without the need for any spotter. Finally we present the plan for the future upgrades, mostly dedicated toward improving the performance and reliability of the system. Our first upgrade called NGS2, a project lead by the Australian National University, based a focal plane camera will replace the current low throughput natural guide wavefront sensor. On a longer term, we are also planning the (re-)integration of our third deformable mirror, lost during the early phase of commissioning. Early plans to improve the reliability of our laser will be presented.

The Gemini Multi-conjugate adaptive optics System (GeMS) at the Gemini South telescope in Cerro Pach{\'o}n is the first sodium-based multi-Laser Guide Star (LGS) adaptive optics system. It uses five LGSs and two deformable mirrors to measure and compensate for atmospheric distortions. The GeMS project started in 1999, and saw first light in 2011. It is now in regular operation, producing images close to the diffraction limit in the near infrared, with uniform quality over a field of view of two square arcminutes. The present paper (I) is the first one in a two-paper review of GeMS. It describes the system, explains why and how it was built, discusses the design choices and trade-offs, and presents the main issues encountered during the course of the project. Finally, we briefly present the results of the system first light., Comment: 17 pages, 7 figures, Accepted for publication in MNRAS

e13523Background: LGG grow progressively over time before transforming to high-grade gliomas. A mathematical model of evolution of gliomas, taking into account not only the proliferation but also m...

With two to three deformable mirrors, three Natural Guide Stars (NGS) and five sodium Laser Guide Stars (LGS), the Gemini Multi-Conjugate Adaptive Optics System (Gemini MCAO a.k.a. GeMS) will be the first facility-class MCAO capability to be offered for regular science observations starting in 2013A. The engineering and science commissioning phase of the project was kicked off in January 2011 when the Gemini South Laser Guide Star Facility (GS LGSF) propagated its 50W laser above the summit of Cerro Pachon, Chile. GeMS commissioning has proceeded throughout 2011 and the first half of 2012 at a pace of one 6- to 10-night run per month with a 5-month pause during the 2011 Chilean winter. This paper focuses on the LGSF-side of the project and provides an overview of the LGSF system and subsystems, their top-level specifications, design, integration with the telescope, and performance throughout commissioning and beyond. Subsystems of the GS LGSF include: (i) a diode-pumped solid-state 1.06+1.32 micron sum-frequency laser capable of producing over 50W of output power at the sodium wavelength (589nm); (ii) Beam Transfer Optics (BTO) that transport the 50W beam up the telescope, split the beam five-ways and configure the five 10W beams for projection by the Laser Launch Telescope (LLT) located behind the Gemini South 8m telescope secondary mirror; and (iii) a variety of safety systems to ensure safe laser operations for observatory personnel and equipment, neighbor observatories, as well as passing aircrafts and satellites.

The Gemini Multi-Conjugate Adaptive Optics System (GeMS} began its on-sky commissioning in January 20ll. The system provides high order wide-field corrections using a constellation of five Laser Guide Stars. In December 20ll, commissioning culminated in images with a FWHM of 80±2mas at 1.65 microns (H band} over an 87 x 87 arcsccond field of view. The first images have already demonstrated the scientific potential of GeMS, and after more than a year of commissioning GeMS is finally close to completion and ready for science. This paper presents a general status of the GeMS project and summarizes the achievements made during more than a year of commissioning. The characterization of GeMS performance is presented in a companion paper: "GeMS on-sky results" , R.igaut ct al. Here we report on the sub-systems' performance, discuss current limitations and present proposed upgrades. The integration of GeMS into the observatory operational scheme is detailed. Finally, we present the plans for next year's operations with GeMS.

GeMS, the Gemini Laser Guide Star Multi-Conjugate Adaptive Optics facility system, has seen first light in December 2011, and has already produced images with H band Strehl ratio in excess of 35% over fields of view of 85x85 arcsec, fulfilling the MCAO promise. In this paper, we report on these early results, analyze trends in performance, and concentrate on key or novel aspects of the system, like centroid gain estimation, on-sky non­ common path aberration estimation. We also present the first astrometric analysis, showing very encouraging results.

We will discuss the implementation and calibration of a new GPS based water vapor monitor installed at Cerro Pachon for the Gemini Observatory in Chile. The primary goal of this system is the use of GPS signals to monitor the Precipitable Water Vapor (PWV) in the atmosphere in near-realtime. This is vital in maximizing the efficiency of queue observations in the thermal infrared in which atmospheric transmission and sensitivity is highly dependent on PWV. The GPS WV system was calibrated using near-IR spectroscopy of known water lines based on atmosphere models and imaging the thermal mid-IR background. Observations were conducted using the near-IR imager/spectrometer Phoenix for K, L, and M-band spectroscopy (2.2μm, 3.5μm, 4.5μm) and the mid-infrared imager/spectrometer T-ReCS imaging between 8-20 μm.

2040 Background: Glioblastoma (GB) is the most common malignant primary brain tumor in adults. The standard therapy for newly diagnosed glioblastoma is surgical resection followed by radiotherapy (...