Multitask Learning to Improve Egocentric Action Recognition

In this work we employ multitask learning to capitalize on the structure that exists in related supervised tasks to train complex neural networks. It allows training a network for multiple objectives in parallel, in order to improve performance on at least one of them by capitalizing on a shared representation that is developed to accommodate more information than it otherwise would for a single task. We employ this idea to tackle action recognition in egocentric videos by introducing additional supervised tasks. We consider learning the verbs and nouns from which action labels consist of and predict coordinates that capture the hand locations and the gaze-based visual saliency for all the frames of the input video segments. This forces the network to explicitly focus on cues from secondary tasks that it might otherwise have missed resulting in improved inference. Our experiments on EPIC-Kitchens and EGTEA Gaze+ show consistent improvements when training with multiple tasks over the single-task baseline. Furthermore, in EGTEA Gaze+ we outperform the state-of-the-art in action recognition by 3.84%. Apart from actions, our method produces accurate hand and gaze estimations as side tasks, without requiring any additional input at test time other than the RGB video clips.Comment: 10 pages, 3 figures, accepted at the 5th Egocentric Perception, Interaction and Computing (EPIC) workshop at ICCV 2019, code repository: https://github.com/georkap/hand_track_classificatio

The phosphate potential maintained by mitochondria in State 4 is proportional to the proton-motive force

AbstractEvidence is presented for a proportional relationship between the extramitochondrial phosphate potential (ΔGexp) and the proton-motive force (Δ\̃gmH+) across the mitochondrial membrane in rat-liver mitochondria oxidising succinate in State 4, when Δ\̃gmH+ is varied by addition of uncouplers or malonate. This relationship was found when precautions were taken to minimise interference with the determination of ΔGpex and Δ\̃gmH+ by intramitochondrial nucleotides, adenylate kinase activity, the quenching method, and Δ\̃gmH+-dependent changes in matrix volume. A non-proportional ΔGpex/Δ\̃gmH+ relationship was obtained when these precautions were omitted. Our results do not support mosaic protonic coupling, but are not necessarily in conflict with other localised coupling schemes

Macroevolutionary and macroecological response of Iberian rodents to late Neogene climatic oscillations and events

Biozones are routinely used for chronological purposes, but their nature is seldomly questioned. Here, we attempt to find the evolutionary-ecological basis for Iberian rodent biozones for the interval 8.5-2 Ma based on currently available paleontological, stratigraphic and paleoclimatic information. Our comparison of biozone boundary age uncertainty intervals to records of marine SST, δ18O and δ13C, terrestrial hydrological proxies and astronomical parameters suggests an orbitally forced climatic origin for the majority of biozones. Zone boundary ages during the late Miocene are mostly associated with humidity changes during 1.2-Myr obliquity nodes and 405-kyr eccentricity minima. Tectonics and strong regional cooling may additionally explain faunal change during the Messinian (7-5 Ma). A partly reversed pattern characterizes most Pliocene zone boundaries, which are mostly associated with wetter conditions during obliquity nodes and 405-kyr eccentricity maxima. A third configuration culminates in the early Pleistocene and consists of the combination of strong obliquity amplitude maxima and 2.4-Myr eccentricity minima. It is suggested that larger-scale, European Neogene mammal (MN) units have an astronomical basis as well, with an important role of 2.4-Myr eccentricity cycle and the 1.2-Myr obliquity cycle, with the latter becoming especially important after the mid-Miocene cooling (∼14 Ma). Whereas rodent events on the Iberian Peninsula during the late Miocene are shaped by replacements within resident communities dominated by dry-adapted clades of true mice (Murinae) and hamsters (Cricetinae), transitions during the cooler Pliocene involve invasions of newly emerging Eurasian clades of 'microtoid hamsters' and voles (Arvicolinae) preferring wetter and cooler environments. A new model of stepwise clade displacement is proposed in which the combination of long-period Milankovitch cycles and gradual long-term climatic change allows for the periodic functioning of migration corridors, along which increasingly pervasive dispersal events by members of new clades cause the gradual extinction of old clades

Aspartame and Phe-Containing Degradation Products in Soft Drinks across Europe

Phenylketonuria and tyrosinemia type 1 are treated with dietary phenylalanine (Phe) restriction. Aspartame is a Phe-containing synthetic sweetener used in many products, including many 'regular' soft drinks. Its amount is (often) not declared; therefore, patients are advised not to consume aspartame-containing foods. This study aimed to determine the variation in aspartame concentrations and its Phe-containing degradation products in aspartame-containing soft drinks. For this, an LC-MS/MS method was developed for the analysis of aspartame, Phe, aspartylphenylalanine, and diketopiperazine in soft drinks. In total, 111 regularly used soft drinks from 10 European countries were analyzed. The method proved linear and had an inter-assay precision (CV%) below 5% for aspartame and higher CVs% of 4.4-49.6% for the degradation products, as many concentrations were at the limit of quantification. Aspartame and total Phe concentrations in the aspartame-containing soft drinks varied from 103 to 1790 µmol/L (30-527 mg/L) and from 119 to 2013 µmol/L (20-332 mg/L), respectively, and were highly variable among similar soft drinks bought in different countries. Since Phe concentrations between drinks and countries highly vary, we strongly advocate the declaration of the amount of aspartame on soft drink labels, as some drinks may be suitable for consumption by patients with Phe-restricted diets

A new rodent chronology for the late Neogene of Spain

The number of late Neogene Spanish micromammal-containing continental sections with a correlation to the Geomagnetic Time Scale is steadily growing. Nonetheless, well-calibrated sections with dense micromammal records are still rare, biostratigraphic correlations between basins are not straightforward, and ages of uncalibrated sites are poorly constrained. Here, we aim at improving the chronology of Iberian micromammal sections and sites for the interval 8.5–2 Ma by: (i) analyzing qualitative and quantitative similarities between rodent assemblages and turnover in the different basins, (ii) formulating a system of fifteen Iberian assemblage biozones, and (iii) constraining the ages of zone boundaries, assuming isochroneity across basins. Age uncertainty ranges for most known Iberian micromammal sites are obtained by combining regional biozone boundary ages with local magnetostratigraphic records, sedimentation rates and/or evolutionary rates. In addition, our results include new, integrated stratigraphic records from the Jumilla-La Celia and Teruel Basins, which are used to constrain the thus far poorly dated interval covering the latest Tortonian and earliest Messinian (8–7 Ma)

Macroevolutionary and macroecological response of Iberian rodents to late Neogene climatic oscillations and events

Biozones are routinely used for chronological purposes, but their nature is seldomly questioned. Here, we attempt to find the evolutionary-ecological basis for Iberian rodent biozones for the interval 8.5–2 Ma based on currently available paleontological, stratigraphic and paleoclimatic information. Our comparison of biozone boundary age uncertainty intervals to records of marine SST, δ18O and δ13C, terrestrial hydrological proxies and astronomical parameters suggests an orbitally forced climatic origin for the majority of biozones. Zone boundary ages during the late Miocene are mostly associated with humidity changes during 1.2-Myr obliquity nodes and 405-kyr eccentricity minima. Tectonics and strong regional cooling may additionally explain faunal change during the Messinian (7–5 Ma). A partly reversed pattern characterizes most Pliocene zone boundaries, which are mostly associated with wetter conditions during obliquity nodes and 405-kyr eccentricity maxima. A third configuration culminates in the early Pleistocene and consists of the combination of strong obliquity amplitude maxima and 2.4-Myr eccentricity minima. It is suggested that larger-scale, European Neogene mammal (MN) units have an astronomical basis as well, with an important role of 2.4-Myr eccentricity cycle and the 1.2-Myr obliquity cycle, with the latter becoming especially important after the mid-Miocene cooling (∼14 Ma). Whereas rodent events on the Iberian Peninsula during the late Miocene are shaped by replacements within resident communities dominated by dry-adapted clades of true mice (Murinae) and hamsters (Cricetinae), transitions during the cooler Pliocene involve invasions of newly emerging Eurasian clades of ‘microtoid hamsters’ and voles (Arvicolinae) preferring wetter and cooler environments. A new model of stepwise clade displacement is proposed in which the combination of long-period Milankovitch cycles and gradual long-term climatic change allows for the periodic functioning of migration corridors, along which increasingly pervasive dispersal events by members of new clades cause the gradual extinction of old clades