NAROO program Perlbarg, A.-C.; Desmars, J.; Robert, V. ...
Astronomy and astrophysics (Berlin),
12/2023, Volume:
680
Journal Article
Peer reviewed
Open access
Context.
The New Astrometric Reduction of Old Observations (NAROO) program is dedicated to the measurement of astrophotographic plates and the analysis of old observations for scientific purposes. ...One of the objectives of the NAROO program is to provide accurate positional measurements of small Solar System bodies in order to improve our knowledge of their orbits and dynamics.
Aims.
Focused on potentially hazardous asteroids (PHAs), which are near-Earth asteroids (NEAs) making very close encounters with the Earth, this paper aims to emphasize the value of old photographic plate observations. As they provide accurate astrometric measurements over a large time interval, such observations are essential to determine reliable orbits and to detect small accelerations, such as the Yarkovsky effect.
Methods.
Photographic plates consist of a substantial source of old observations of Solar System objects. From existing databases, we identified old and precovery observations of PHAs, which are fortuitous observations made before their discovery. We used the NAROO machine to digitize the plates, and we performed the astrometric reduction with the
Gaia
DR3 reference star catalog. We added the results to the observation dataset of PHAs in order to determine new orbital solutions and possibly detect the Yarkovsky effect with the Numerical Integration of the Motion of an Asteroid (NIMA) program. In addition, we considered a possible timing error in the orbit adjustment, which is generally not taken into account in such problems, and show its influence.
Results.
We were able to find precovery observations of PHAs in photographic plate databases. Their introduction in the dataset show a significant improvement of the accuracy of the new orbital solutions. They also help in detecting and measuring the Yarkovsky effect and improve its accuracy. Hence, we demonstrate the interest of the reduction or new reduction of old photographic plates for the orbit determination of PHAs.
The NAROO digitization center Robert, V.; Desmars, J.; Lainey, V. ...
Astronomy and astrophysics (Berlin),
08/2021, Volume:
652
Journal Article
Peer reviewed
Open access
The New Astrometric Reduction of Old Observations (NAROO) center can be found at the Paris Observatory in Meudon, and it is dedicated to the measurement of astrophotographic plates and the analysis ...of old observations. The NAROO digitizer consists of a granite-based Newport-Microcontrol open-frame air-bearing
XY
positioning table, a scientific sCMOS camera, and a telecentric optical system. The plate holder assembly is suited for mounting glass plates up to 350 mm squared. The machine positioning stability is better than 15 nm, and its repeatability is better than 40 nm. With real photographic plate data, we were able to produce measurements with an accuracy better than 65 nm. The renewed interest about photographic plates concerns the expansion of the database of transient objects evolving in time, since digitization now makes it possible to measure images with a high level of accuracy and to identify all the available objects. The information extracted from such materials can be of an astrometric, photometric, and spectroscopic nature, when not purely imaging, with consequences in planetology, near-Earth asteroid risk assessment, astrophysical phenomena, and general relativity, to mention but a few. Through our scientific program in the
Gaia
era, we detail examples of current and upcoming uses for the community. We invite researchers to use our facilities and digitize their collection by answering our call for proposals.
Context.
With the advent of large-scale astronomical surveys, such as the Zwicky Transient Facility (ZTF) and the forthcoming
Vera C. Rubin
Observatory’s Legacy Survey of Space and Time (LSST), the ...number of alerts generated by transient, variable, and moving astronomical objects is growing rapidly, reaching millions of alerts per night. Concerning the minor planets of the Solar System, their identification requires linking the alerts for many observations over a potentially lengthy period of time, leading to a very large combinatorial number.
Aims.
The goal is to demonstrate how a third-party module dedicated to the identification of new minor planets of the Solar System can be integrated with the Fink alert broker real-time operations, which deals with massive alert data streams produced by large-scale surveys.
Methods.
Our analysis takes advantage of the scientific surplus brought on by the Fink alert broker classification capabilities to first reduce the 111 275 131 processed alerts from ZTF between November 2019 and December 2022 (755 observation nights) to only 389 530 new Solar System alert candidates over the same period. We implemented a simple, yet pedagogical linking algorithm called Fink-FAT to create trajectory candidates in real time from alert data and extract orbital parameters. The analysis was validated on ZTF alert packets linked to confirmed Solar System objects from the Minor Planet Center (MPC) database. Finally, the candidates were confronted with follow-up observations.
Results.
Between November 2019 and December 2022, Fink-FAT extracted 327 new orbits from candidate Solar System objects at the time of the observations, of which 65 had still remained unreported in the MPC database as of March 2023. After two late follow-up observation campaigns of six orbit candidates, four were associated with known minor planets of the Solar System, and two still remain unknown. In terms of performance, Fink-FAT took under 3 h to link alerts into trajectory candidates and to extract the orbital elements over the three years of Fink data, using a modest hardware configuration.
Conclusions.
Despite a much lower efficiency than present linking algorithms, Fink-FAT reaches a high level of purity in reconstructing orbits and it runs fast, making it suitable for the real-time discovery of new minor planets. Fink-FAT is deployed in the Fink broker and analyzes, in real time, the alert data from the ZTF survey by regularly extracting new candidates for Solar System objects. Tests of scalability also show that Fink-FAT is capable of handling the even larger volume of alert data that will be sent by the
Rubin
Observatory’s real-time difference image analysis processing.
NAROO program Perlbarg, A-C; Desmars, J.; Robert, V ...
Astronomy & astrophysics,
12/2023, Volume:
680
Journal Article
Peer reviewed
Open access
Context. The New Astrometric Reduction of Old Observations (NAROO) program is dedicated to the measurement of astrophotographic plates and the analysis of old observations for scientific purposes. ...One of the objectives of the NAROO program is to provide accurate positional measurements of small Solar System bodies in order to improve our knowledge of their orbits and dynamics.Aims. Focused on potentially hazardous asteroids (PHAs), which are near-Earth asteroids (NEAs) making very close encounters with the Earth, this paper aims to emphasize the value of old photographic plate observations. As they provide accurate astrometric measurements over a large time interval, such observations are essential to determine reliable orbits and to detect small accelerations, such as the Yarkovsky effect.Methods. Photographic plates consist of a substantial source of old observations of Solar System objects. From existing databases, we identified old and precovery observations of PHAs, which are fortuitous observations made before their discovery. We used the NAROO machine to digitize the plates, and we performed the astrometric reduction with the Gaia DR3 reference star catalog. We added the results to the observation dataset of PHAs in order to determine new orbital solutions and possibly detect the Yarkovsky effect with the Numerical Integration of the Motion of an Asteroid (NIMA) program. In addition, we considered a possible timing error in the orbit adjustment, which is generally not taken into account in such problems, and show its influence.Results. We were able to find precovery observations of PHAs in photographic plate databases. Their introduction in the dataset show a significant improvement of the accuracy of the new orbital solutions. They also help in detecting and measuring the Yarkovsky effect and improve its accuracy. Hence, we demonstrate the interest of the reduction or new reduction of old photographic plates for the orbit determination of PHAs.
The NAROO digitization center Robert, V; Desmars, J; Lainey, V ...
Astronomy & astrophysics,
08/2021, Volume:
652
Journal Article
Peer reviewed
Open access
The New Astrometric Reduction of Old Observations (NAROO) center can be found at the Paris Observatory in Meudon, and it is dedicated to the measurement of astrophotographic plates and the analysis ...of old observations. The NAROO digitizer consists of a granite-based Newport-Microcontrol open-frame air-bearing XY positioning table, a scientific sCMOS camera, and a telecentric optical system. The plate holder assembly is suited for mounting glass plates up to 350 mm squared. The machine positioning stability is better than 15 nm, and its repeatability is better than 40 nm. With real photographic plate data, we were able to produce measurements with an accuracy better than 65 nm. The renewed interest about photographic plates concerns the expansion of the database of transient objects evolving in time, since digitization now makes it possible to measure images with a high level of accuracy and to identify all the available objects. The information extracted from such materials can be of an astrometric, photometric, and spectroscopic nature, when not purely imaging, with consequences in planetology, near-Earth asteroid risk assessment, astrophysical phenomena, and general relativity, to mention but a few. Through our scientific program in the Gaia era, we detail examples of current and upcoming uses for the community. We invite researchers to use our facilities and digitize their collection by answering our call for proposals.
With the advent of large-scale astronomical surveys such as the Zwicky Transient Facility (ZTF), the number of alerts generated by transient, variable and moving astronomical objects is growing ...rapidly, reaching millions per night. Concerning solar system minor planets, their identification requires linking the alerts of many observations over a potentially large time, leading to a very large combinatorial number. This work aims to identify new candidates for solar system objects from massive alert data streams produced by large-scale surveys, such as the ZTF and the Vera C. Rubin Observatory's Legacy Survey of Space and Time. Our analysis used the Fink alert broker capabilities to reduce the 111,275,131 processed alerts from ZTF between November 2019 and December 2022 to only 389,530 new solar system alert candidates over the same period. We then implemented a linking algorithm, Fink-FAT, to create real-time trajectory candidates from alert data and extract orbital parameters. The analysis was validated on ZTF alert packets linked to confirmed solar system objects from the Minor Planet Center database. Finally, the results were confronted against follow-up observations. Between November 2019 and December 2022, Fink-FAT extracted 327 new orbits from solar system object candidates at the time of the observations, over which 65 were still unreported in the MPC database as of March 2023. After two late follow-up observation campaigns of six orbit candidates, four were associated with known solar system minor planets, and two remain unknown. Fink-FAT is deployed in the Fink broker and successfully analyzes in real time the alert data from the ZTF survey by regularly extracting new candidates for solar system objects. Our scalability tests also show that Fink-FAT can handle the even larger volume of alert data that the Rubin Observatory will send.
Heart rate has natural fluctuations that are typically ascribed to autonomic function. Recent evidence suggests that conscious processing can affect the timing of the heartbeat. We hypothesized that ...heart rate is modulated by conscious processing and therefore dependent on attentional focus. To test this, we leverage the observation that neural processes synchronize between subjects by presenting an identical narrative stimulus. As predicted, we find significant inter-subject correlation of heart rate (ISC-HR) when subjects are presented with an auditory or audiovisual narrative. Consistent with our hypothesis, we find that ISC-HR is reduced when subjects are distracted from the narrative, and higher ISC-HR predicts better recall of the narrative. Finally, patients with disorders of consciousness have lower ISC-HR, as compared to healthy individuals. We conclude that heart rate fluctuations are partially driven by conscious processing, depend on attentional state, and may represent a simple metric to assess conscious state in unresponsive patients.
Display omitted
•Narrative stimuli can synchronize fluctuations of heart rate between individuals•This interpersonal synchronization is modulated by attention and predicts memory•These effects on heart rate cannot be explained by modulation of respiratory patterns•Synchrony is lower in patients with disorders of consciousness
Stories affect our hearts and bind us together. Pérez et al. show that attention to narratives can synchronize fluctuations of heart rate between individuals. Heart synchronization predicts memory and cannot be explained by respiration. Finally, synchrony is lower in patients with disorders of consciousness and might inform prognosis.
The burden of traumatic brain injury (TBI) poses a large public health and societal problem, but the characteristics of patients and their care pathways in Europe are poorly understood. We aimed to ...characterise patient case-mix, care pathways, and outcomes of TBI.
CENTER-TBI is a Europe-based, observational cohort study, consisting of a core study and a registry. Inclusion criteria for the core study were a clinical diagnosis of TBI, presentation fewer than 24 h after injury, and an indication for CT. Patients were differentiated by care pathway and assigned to the emergency room (ER) stratum (patients who were discharged from an emergency room), admission stratum (patients who were admitted to a hospital ward), or intensive care unit (ICU) stratum (patients who were admitted to the ICU). Neuroimages and biospecimens were stored in repositories and outcome was assessed at 6 months after injury. We used the IMPACT core model for estimating the expected mortality and proportion with unfavourable Glasgow Outcome Scale Extended (GOSE) outcomes in patients with moderate or severe TBI (Glasgow Coma Scale GCS score ≤12). The core study was registered with ClinicalTrials.gov, number NCT02210221, and with Resource Identification Portal (RRID: SCR_015582).
Data from 4509 patients from 18 countries, collected between Dec 9, 2014, and Dec 17, 2017, were analysed in the core study and from 22 782 patients in the registry. In the core study, 848 (19%) patients were in the ER stratum, 1523 (34%) in the admission stratum, and 2138 (47%) in the ICU stratum. In the ICU stratum, 720 (36%) patients had mild TBI (GCS score 13–15). Compared with the core cohort, the registry had a higher proportion of patients in the ER (9839 43%) and admission (8571 38%) strata, with more than 95% of patients classified as having mild TBI. Patients in the core study were older than those in previous studies (median age 50 years IQR 30–66, 1254 28% aged >65 years), 462 (11%) had serious comorbidities, 772 (18%) were taking anticoagulant or antiplatelet medication, and alcohol was contributory in 1054 (25%) TBIs. MRI and blood biomarker measurement enhanced characterisation of injury severity and type. Substantial inter-country differences existed in care pathways and practice. Incomplete recovery at 6 months (GOSE <8) was found in 207 (30%) patients in the ER stratum, 665 (53%) in the admission stratum, and 1547 (84%) in the ICU stratum. Among patients with moderate-to-severe TBI in the ICU stratum, 623 (55%) patients had unfavourable outcome at 6 months (GOSE <5), similar to the proportion predicted by the IMPACT prognostic model (observed to expected ratio 1·06 95% CI 0·97–1·14), but mortality was lower than expected (0·70 0·62–0·76).
Patients with TBI who presented to European centres in the core study were older than were those in previous observational studies and often had comorbidities. Overall, most patients presented with mild TBI. The incomplete recovery of many patients should motivate precision medicine research and the identification of best practices to improve these outcomes.
European Union 7th Framework Programme, the Hannelore Kohl Stiftung, OneMind, and Integra LifeSciences Corporation.
Cerebellum is a key structure for functional motor recovery after stroke. Enhancing the cerebello-motor pathway by paired associative stimulation (PAS) might improve upper limb function. Here, we ...conducted a randomized, double-blind, sham-controlled pilot trial investigating the efficacy of a 5-day treatment of cerebello-motor PAS coupled with physiotherapy for promoting upper limb motor function compared to sham stimulation. The secondary objectives were to determine in the active treated group (i) whether improvement of upper limb motor function was associated with changes in corticospinal excitability or changes in functional activity in the primary motor cortex and (ii) whether improvements were correlated to the structural integrity of the input and output pathways. To that purpose, hand dexterity and maximal grip strength were assessed along with TMS recordings and multimodal magnetic resonance imaging, before the first treatment, immediately after the last one and a month later. Twenty-seven patients were analyzed. Cerebello-motor PAS was effective compared to sham in improving hand dexterity (
p
: 0.04) but not grip strength. This improvement was associated with increased activation in the ipsilesional primary motor cortex (
p
: 0.04). Moreover, the inter-individual variability in clinical improvement was partly explained by the structural integrity of the afferent (
p
: 0.06) and efferent pathways (
p
: 0.02) engaged in this paired associative stimulation (i.e., cortico-spinal and dentato-thalamo-cortical tracts). In conclusion, cerebello-motor-paired associative stimulation combined with physiotherapy might be a promising approach to enhance upper limb motor function after stroke.
Clinical Trial Registration
URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT 02284087.
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