24 research outputs found
Toloka Visual Question Answering Benchmark
In this paper, we present Toloka Visual Question Answering, a new
crowdsourced dataset allowing comparing performance of machine learning systems
against human level of expertise in the grounding visual question answering
task. In this task, given an image and a textual question, one has to draw the
bounding box around the object correctly responding to that question. Every
image-question pair contains the response, with only one correct response per
image. Our dataset contains 45,199 pairs of images and questions in English,
provided with ground truth bounding boxes, split into train and two test
subsets. Besides describing the dataset and releasing it under a CC BY license,
we conducted a series of experiments on open source zero-shot baseline models
and organized a multi-phase competition at WSDM Cup that attracted 48
participants worldwide. However, by the time of paper submission, no machine
learning model outperformed the non-expert crowdsourcing baseline according to
the intersection over union evaluation score.Comment: 16 pages; see https://toloka.ai/challenges/wsdm2023/ for more detail
Endogenous Isoquinoline Alkaloids Agonists of Acid-Sensing Ion Channel Type 3
Acid-sensing ion channels (ASICs) ASIC3 expressed mainly in peripheral sensory neurons play an important role in pain perception and inflammation development. In response to acidic stimuli, they can generate a unique biphasic current. At physiological pH 7.4, human ASIC3 isoform (hASIC3) is desensitized and able to generate only a sustained current. We found endogenous isoquinoline alkaloids (EIAs), which restore hASIC3 from desensitization and recover the transient component of the current. Similarly, rat ASIC3 isoform (rASIC3) can also be restored from desensitization (at pH < 7.0) by EIAs with the same potency. At physiological pH and above, EIAs at high concentrations were able to effectively activate hASIC3 and rASIC3. Thus, we found first endogenous agonists of ASIC3 channels that could both activate and prevent or reverse desensitization of the channel. The decrease of EIA levels could be suggested as a novel therapeutic strategy for treatment of pain and inflammation
NDACC harmonized formaldehyde time-series from 21 FTIR stations covering a wide range of column abundances
Among the more than 20 ground-based FTIR (Fourier transform infrared) stations currently operating around the globe, only a few have provided formaldehyde (HCHO) total column time series until now. Although several independent studies have shown that the FTIR measurements can provide formaldehyde total columns with good precision, the spatial coverage has not been optimal for providing good diagnostics for satellite or model validation. Furthermore, these past studies used different retrieval settings, and biases as large as 50 % can be observed in the HCHO total columns depending on these retrieval choices, which is also a weakness for validation studies combining data from different ground-based stations.
For the present work, the HCHO retrieval settings have been optimized based on experience gained from past studies and have been applied consistently at the 21 participating stations. Most of them are either part of the Network for the Detection of Atmospheric Composition Change (NDACC) or under consideration for membership. We provide the harmonized settings and a characterization of the HCHO FTIR products. Depending on the station, the total systematic and random uncertainties of an individual HCHO total column measurement lie between 12 % and 27 % and between 1 and 11×1014 molec cm−2, respectively. The median values among all stations are 13 % and 2.9×1014 molec cm−2 for the total systematic and random uncertainties.
This unprecedented harmonized formaldehyde data set from 21 ground-based FTIR stations is presented and its comparison with a global chemistry transport model shows consistency in absolute values as well as in seasonal cycles. The network covers very different concentration levels of formaldehyde, from very clean levels at the limit of detection (few 1013 molec cm−2) to highly polluted levels (7×1016 molec cm−2). Because the measurements can be made at any time during daylight, the diurnal cycle can be observed and is found to be significant at many stations. These HCHO time series, some of them starting in the 1990s, are crucial for past and present satellite validation and will be extended in the coming years for the next generation of satellite missions.This study has been supported by the ESA
PRODEX project TROVA (2016–2018) funded by the Belgian
Science Policy Office (Belspo)
NDACC harmonized formaldehyde time series from 21 FTIR stations covering a wide range of column abundances
Among the more than 20 ground-based FTIR (Fourier transform infrared) stations currently operating around the globe, only a few have provided formaldehyde (HCHO) total column time series until now. Although several independent studies have shown that the FTIR measurements can provide formaldehyde total columns with good precision, the spatial coverage has not been optimal for providing good diagnostics for satellite or model validation. Furthermore, these past studies used different retrieval settings, and biases as large as 50% can be observed in the HCHO total columns depending on these retrieval choices, which is also a weakness for validation studies combining data from different ground-based stations. For the present work, the HCHO retrieval settings have been optimized based on experience gained from past studies and have been applied consistently at the 21 participating stations. Most of them are either part of the Network for the Detection of Atmospheric Composition Change (NDACC) or under consideration for membership. We provide the harmonized settings and a characterization of the HCHO FTIR products. Depending on the station, the total systematic and random uncertainties of an individual HCHO total column measurement lie between 12% and 27% and between 1 and 11x1014 moleccm-2, respectively. The median values among all stations are 13% and 2.9x1014 moleccm-2 for the total systematic and random uncertainties. This unprecedented harmonized formaldehyde data set from 21 ground-based FTIR stations is presented and its comparison with a global chemistry transport model shows consistency in absolute values as well as in seasonal cycles. The network covers very different concentration levels of formaldehyde, from very clean levels at the limit of detection (few 1013moleccm-2) to highly polluted levels (7x1016moleccm-2). Because the measurements can be made at any time during daylight, the diurnal cycle can be observed and is found to be significant at many stations. These HCHO time series, some of them starting in the 1990s, are crucial for past and present satellite validation and will be extended in the coming years for the next generation of satellite missions
Carbon dioxide retrieval from OCO-2 satellite observations using the RemoTeC algorithm and validation with TCCON measurements
Les premières mesures TCCON de CO2 par FTIR depuis le sol dans une mégapole Européenne : comparaison avec un site rural et validation des mesures satellitaires
Total Carbon Column Observing Network (TCCON) is a global network of ground-based Fourier transform spectrometers which monitor column-averaged abundances (Xgas) of atmospheric gases by direct solar absorption spectroscopy. TCCON-Paris is the first European TCCON site operated in a megacity, located in the centre of Paris. The manuscript first describes the instrument and the characterisation of its performance. The instrumental line shape is investigated by using low-pressure HCl gas cell measurements. The instrument stability is determined by using the Allan variance approach. We have participated in a blind intercomparison test of measuring N2O gas columns in low-pressure cells. The results of our analysis have helped to identify an error in the référencé measurements. An overview of the GGG software package used by TCCON is given. Quality control procedure and biult-in filters are discussed. Different acquisition setups are compared in order to improve the precision of TCCON-Paris measurements. We investigate, as much CO2 a priori profiles provided by GGG are suited to retrieve CO2 abundances in Paris. From complementary CO2 in-situ and LIDAR measurements at the TCCON-Paris station, we construct improved CO2 a priori profiles that comply with the local ground conditions. An overview of the method and discussion of the sensitivity and biases of the retrieved XCO2 are given. Mobile, low-resolution instruments (EM27/SUN) used to allow the intercalibration of distant TCCON instruments. EM27/SUN was used as a transferable reference between the TCCON-Orleans and TCCON-Paris sites. Differences in retrieved XCO2 between EM27/SUN and TCCON are discussed.Installée au cœur du quartier Latin, la station TCCON-Paris est le premier site du réseau TCCON exploité dans une mégapole européenne. TCCON est un réseau international de spectromètres FTIR qui surveillent l’abondance de gaz à effet de serre de l’atmosphère par spectroscopie d'absorption solaire directe. Le manuscrit décrit d'abord l'instrument FTS-Paris et la caractérisation de ses performances: détermination de la fonction d'appareil et étude de la stabilité de l'instrument par l'approche de variance Allan. Les résultats TCCON obtenus par GGG (code de transfert radiatif utilisé par le réseau TCCON) sont présentés, ainsi que les études réalisées pour améliorer la précision des mesures de la TCCON-Paris, notamment, l’étude des profils a prioiri de CO2 fournis par GGG (sans prendre en compte les émissions anthropogéniques) dans le cas de Paris. La méthode développée dans le cadre de ce doctorat s’appuie sur les conditions locales et réelles (mesures in situ et Lidar) pour modéliser des profils a priori de CO2 plus adaptés à Paris. Une description détaillée et illustrée est présentée, ainsi que l’étude de sensibilité de cette méthode et les corrections introduites. Le manuscrit termine sur l’utilisation de spectromètre mobiles FTIR à basse résolution (EM27/SUN) pour étudier l’inter-calibration des instruments entre les sites TCCON. Deux campagnes de mesures ont été réalisées pour caractériser les différences possibles entre les sites TCCON-Paris et TCCON-Orléans afin de transférer le standard WMO sur le site de Paris (survol d’avion interdit). Les résultats sont présentées et discutées
Influence of the a priori profile on CO2 total columns at Paris during pollution episodes
International audienceGround-based Fourier transform spectrometry (FTIR) using solar absorption spectroscopy is a powerful tool for monitoring atmospheric trace gases and validate satellite measurements. The Total Carbon Column Observing Network (TCCON) is an international FTIR network operating in the near-infrared spectral region and dedicated to the retrieval of greenhouse gases. Accurate and precise column-averaged abundances of atmospheric constituents like CO2, CH4, CO, N2O, HF, H2O and HDO are provided on a routinely basis. These data are linked to the WMO reference scale and used to validate satellite data worldwide. Only two TCCON instruments are operated in megacities that globally are important sources of anthropogenic CO2: one instrument is located in Pasadena, California (United States) and the other one in Paris, France. Paris is the third European megacity. We address the question in as much a priori CO2 profiles provided by GFIT (TCCON retrieval algorithm) are suited to retrieve CO2 abundances during pollution episodes in Paris. CO2 a priori profiles from GFIT, as provided by the standard TCCON retrieval algorithm, yield typical surface volume mixing ratios (VMR) of CO2 between 385 and 415 ppm, while in situ measurements at the ground can easily values as high as 450 ppm. From complementary in-situ CO2 and LIDAR measurements at the TCCON-Paris station, we construct improved a priori profiles that comply with the local conditions at the ground. These new a priori profiles are then incorporated into the GFIT code to study their influence on the retrieved total column of CO2. The presentation will give an overview of the method and discuss the sensitivity of the retrieved XCO2 to the improved a priori profile
Influence of the a priori profile on CO2 total columns at Paris during pollution episodes
International audienceGround-based Fourier transform spectrometry (FTIR) using solar absorption spectroscopy is a powerful tool for monitoring atmospheric trace gases and validate satellite measurements. The Total Carbon Column Observing Network (TCCON) is an international FTIR network operating in the near-infrared spectral region and dedicated to the retrieval of greenhouse gases. Accurate and precise column-averaged abundances of atmospheric constituents like CO2, CH4, CO, N2O, HF, H2O and HDO are provided on a routinely basis. These data are linked to the WMO reference scale and used to validate satellite data worldwide. Only two TCCON instruments are operated in megacities that globally are important sources of anthropogenic CO2: one instrument is located in Pasadena, California (United States) and the other one in Paris, France. Paris is the third European megacity. We address the question in as much a priori CO2 profiles provided by GFIT (TCCON retrieval algorithm) are suited to retrieve CO2 abundances during pollution episodes in Paris. CO2 a priori profiles from GFIT, as provided by the standard TCCON retrieval algorithm, yield typical surface volume mixing ratios (VMR) of CO2 between 385 and 415 ppm, while in situ measurements at the ground can easily values as high as 450 ppm. From complementary in-situ CO2 and LIDAR measurements at the TCCON-Paris station, we construct improved a priori profiles that comply with the local conditions at the ground. These new a priori profiles are then incorporated into the GFIT code to study their influence on the retrieved total column of CO2. The presentation will give an overview of the method and discuss the sensitivity of the retrieved XCO2 to the improved a priori profile
Endogenous Neuropeptide Nocistatin Is a Direct Agonist of Acid-Sensing Ion Channels (ASIC1, ASIC2 and ASIC3)
Acid-sensing ion channel (ASIC) channels belong to the family of ligand-gated ion channels known as acid-sensing (proton-gated) ion channels. Only a few activators of ASICs are known. These are exogenous and endogenous molecules that cause a persistent, slowly desensitized current, different from an acid-induced current. Here we describe a novel endogenous agonist of ASICs—peptide nocistatin produced by neuronal cells and neutrophils as a part of prepronociceptin precursor protein. The rat nocistatin evoked currents in X. laevis oocytes expressing rat ASIC1a, ASIC1b, ASIC2a, and ASIC3 that were very similar in kinetic parameters to the proton-gated response. Detailed characterization of nocistatin action on rASIC1a revealed a proton-like dose-dependence of activation, which was accompanied by a dose-dependent decrease in the sensitivity of the channel to the protons. The toxin mambalgin-2, antagonist of ASIC1a, inhibited nocistatin-induced current, therefore the close similarity of mechanisms for ASIC1a activation by peptide and protons could be suggested. Thus, nocistatin is the first endogenous direct agonist of ASICs. This data could give a key to understanding ASICs activation regulation in the nervous system and also could be used to develop new drugs to treat pathological processes associated with ASICs activation, such as neurodegeneration, inflammation, and pain