Qualitative Abstraction and Inherent Uncertainty in Scene Recognition

The interpretation of scenes, e.g., in videos, is demanding at all levels. At the image processing level it is necessary to apply an "intelligent" segmentation and to determine the objects of interest. For the higher symbolic levels it is a challenging task to perform the transition between quantitative and qualitative data and to determine the relations between objects. Here we assume that the position of objects ("agents") in images and videos will already be determined as a minimal requirement for the further analysis. The interpretation of complex and dynamic scenes with embedded intentional agents is one of the most challenging tasks in current AI and imposes highly heterogeneous requirements. A key problem is the efficient and robust representation of uncertainty. We propose that uncertainty should be distinguished with respect to two different epistemological sources: (1) noisy sensor information and (2) ignorance. In this presentation we propose possible solutions to this class of problems. The use and evaluation of sensory information in the field of robotics shows impressive results especially in the fields of localization (e.g. MCL) and map building (e.g. SLAM) but also imposes serious problems on the successive higher levels of processing due to the probabilistic nature. In this presentation we propose that the use of (a) qualitative abstraction (classic approach) from quantitative to (at least partial) qualitative representations and (b) coherence-based perception validation based on Dempster-Shafer (DST) can help to reduce the problem significantly. The second important probability problem class that will be addressed is ignorance. In our presentation we will focus on reducing missing information by inference. We contrast/compare our experiences in an important field of scene interpretation namely plan and intention recognition. The first approach is based on a logical abductive approach and the second approach in contrast uses a probabilistic approach (Relational Hidden Markov Model (RHMM))

Imbalanced gut microbiota fuels hepatocellular carcinoma development by shaping the hepatic inflammatory microenvironment

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide, and therapeutic options for advanced HCC are limited. Here, we observe that intestinal dysbiosis affects antitumor immune surveillance and drives liver disease progression towards cancer. Dysbiotic microbiota, as seen in Nlrp6(-/-) mice, induces a Toll-like receptor 4 dependent expansion of hepatic monocytic myeloid-derived suppressor cells (mMDSC) and suppression of T-cell abundance. This phenotype is transmissible via fecal microbiota transfer and reversible upon antibiotic treatment, pointing to the high plasticity of the tumor microenvironment. While loss of Akkermansia muciniphila correlates with mMDSC abundance, its reintroduction restores intestinal barrier function and strongly reduces liver inflammation and fibrosis. Cirrhosis patients display increased bacterial abundance in hepatic tissue, which induces pronounced transcriptional changes, including activation of fibro-inflammatory pathways as well as circuits mediating cancer immunosuppression. This study demonstrates that gut microbiota closely shapes the hepatic inflammatory microenvironment opening approaches for cancer prevention and therapy. Steatohepatitis is a chronic hepatic inflammation associated with increased risk of hepatocellular carcinoma progression. Here the authors show that intestinal dysbiosis in mice lacking the inflammasome sensor molecule NLRP6 aggravates steatohepatitis and accelerates liver cancer progression, a process that can be delayed by antibiotic treatment.Peer reviewe

Intuitive Plan Construction and Adaptive Plan Selection

Abstract. Typical tasks of multi agent systems are effective coordination of single agents and their cooperation. Especially in dynamic environments, like the RoboCup soccer domain, the uncertainty of an opponent’s team behavior complicates coordinated team action. This paper presents a novel approach for intuitive multi agent plan construction and adaptive plan selection to attempt these tasks. We introduce a tool designed to represent plans like in tactical playbooks in human soccer which allows easy plan construction, editing and managing. Further we introduce a technique that provides adaptive plan selection in offensive situations by evaluating effectiveness of plans and their actions with statistically interpreted results to improve a team’s style of play. Using experts as a concept for abstracting information about a team’s interaction with another, makes fast accommodated plan selection possible. We briefly describe our software components, examine the performance of our implementation and give an example for rational plan selection i

Incremental generation of abductive explanations for tactical behavior

According to the expert literature on (human) soccer, e.g., the tactical behavior of a soccer team should differ significantly with respect to the tactics and strategy of the opponent team. In the offensive phase the attacking team is usually able to actively select an appropriate tactic with limited regard to the opponent strategy. In contrast, in the defensive phase the more passive recognition of tactical patterns of the behavior of the opponent team is crucial for success. In this paper we present a qualitative, formal, abductive approach, based on a uniform representation of soccer tactics that allows to recognize/explain the tactical and strategical behavior of opponent teams based on past (usually incomplete) observations

The combined Zr and Hf isotope inventory of bulk rock and sequentially leached chondrite samples

The stepwise acid digestion of primitive chondritic meteorites allows the identification of nucleosynthetic isotope anomalies that are otherwise hidden on the bulk rock scale. Here, we present for the first time combined isotope data for acid leachates, residues, and bulk rock aliquots of several primitive chondrites for the geo- and cosmochemically similar elements Zr and Hf. Our analyses reveal significant Zr and Hf isotope anomalies that (i) are complementary between acid leachates and residues and (ii) well-correlated with each other. The observed Zr and Hf anomalies strongly suggest variable contributions of common s-process carrier phases to the different leachates and residues. Ratios of r- (and p-process) Zr and Hf isotopes appear to be uniform in leachates and residues. In contrast to the well-correlated anomalies found in our leaching experiments, nucleosynthetic Zr and Hf isotope signatures seem to be decoupled on the bulk rock scale. This contrast may result from the heterogeneous distribution of neutron-rich Zr material devoid Hf, or alternatively be caused by the presence of anomalous CAI material which overprinted s-process deficits that were initially correlated. In contrast to a previous study, we find no direct evidence for the presence of a third isotopically distinct nucleosynthetic Zr component. (C) 2019 Elsevier Ltd. All rights reserved

Precise determination of low abundance isotopes (Hf-174, W-180 and Pt-190) in terrestrial materials and meteorites using multiple collector ICP-MS equipped with 10(12) Omega Faraday amplifiers

Analytical protocols for measurements of isotope ratios involving low-abundance isotopes Hf-174 (similar to 0.16%), W-180 (similar to 0.12%), and Pt-190 (similar to 0.014%) usingmulti-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) at ca. tenfold improved precision compared to previous studies are presented. The improvements in precision result in part from the use of Faraday amplifiers equipped with 10(12) Omega resistors for collection of the isotope beams of interest, as well as for the isotope beams used to monitor isobaric interferences. For ion currents >5 x 10(-13) A (>50 mV on an amplifier with 10(11) Omega resistor), uncertainties (2 s. d.) of better than 100 ppm are typically achieved for isotope ratios involving Hf-174, W-180 and Pt-190. Terrestrial isotope abundances (atomic percent +/- 2 s.d.) of Hf-174 (0.16106 +/- 0.00006; n=15); W-180(0.11910 +/- 0.00009; n=10); and Pt-190 (0.01286 +/- 0.00005; n = 9) were determined on reference solutions throughout multiple analytical sessions over similar to 3 years. The results, however, rely on the accuracy of the reference value chosen for the isotope ratios employed for mass bias correction and, to a lesser extent, on the accuracy of the exponential mass fractionation law used for mass bias correction. For the precise determination of isotope ratios involving Hf-174, W-180 and Pt-190 in natural materials, efficient chromatographic separation schemes for Hf and W from silicate-rich matrices, and for Pt from iron meteorite matrices, are presented that provide effective separation of the element of interest from interfering elements. First results for Pt suggest that IAB, IIAB and IIIAB iron meteorites exhibit terrestrial Pt-190 abundances within uncertainty. Three chondrite samples exhibit indistinguishable Hf-174 from terrestrial Hf. The isotope abundance of W-180 in meteorites is more variable due to radiogenic W-180 that was produced by Os-184-decay. (C) 2015 Elsevier B.V. All rights reserved

Formation timescales of CV chondrites from component specific Hf-W systematics

Carbonaceous chondrites are an important meteorite group that closely resembles the bulk composition of the solar system. We report the first elemental and isotope dataset for Hf-W in carbonaceous chondrites that includes chondrules, matrix, magnetic fractions as well as bulk compositions. Our study focuses on the three CV3 chondrites, Allende, Vigarano and Bali. Compared to bulk chondrites, matrix splits have low Hf/W ratios and epsilon W-182 compositions, whereas chondrule splits are characterized by high, but more variable, Hf/W ratios and epsilon W-182 compositions. Thus, Hf/W ratios behave complementary between chondrules and matrix in the analysed CV chondrites, supporting the view that both components formed from the same parental reservoir. Strong nucleosynthetic effects were observed in most of the analysed CV3 components, especially in matrices and chondrule splits that were found to have large epsilon W-183 anomalies of several epsilon-units. All separates define a rough correlation between initial W-182/W-184 and W-183/W-184 ratios, in agreement with theoretical model trends based on calculations for stellar nucleosynthesis. Our results, therefore, indicate a heterogeneous distribution of s- and r-process W isotopes among the different CV3 chondrite components, arguing for selective thermal processing of early solar system matter during chondrule formation. After correcting for nucleosynthetic anomalies, chondrules and matrix splits of reduced (Vigarano) as well as oxidised (Allende) CV3 chondrites define a linear correlation in epsilon W-182 vs. Hf-180/W-184 space, which is interpreted as an isochron, covering an age interval within the first similar to 2.6 Ma after solar system formation. As peak metamorphic temperatures for CV3 chondrites were well below the Hf-182-W-182 closure temperature, the resulting isochron within its error most likely defines a common formation interval for all components. The calculated age interval is for the first time based on a combined chondrule-matrix isochron, a marked difference compared to previous studies where only chondrules were analysed. Notably, our formation age interval covers previously reported chondrule formation ages determined using Al-26 and Pb-Pb chronometry, illustrating that chondrule and matrix formation started contemporaneously with CAI formation and lasted over a time interval of about 2-3 Ma. Our results also corroborate previous models from ordinary chondrites, in that chondrite parent bodies were not the first planetesimals to have formed in the early solar system. (C) 2015 Elsevier B.V. All rights reserved

Distribution of p-process Hf-174 in early solar system materials and the origin of nucleosynthetic Hf and W isotope anomalies in Ca-Al rich inclusions

Some nuclides that were produced in supernovae are heterogeneously distributed between different meteoritic materials. In some cases these heterogeneities have been interpreted as the result of interaction between ejecta from a nearby supernova and the nascent solar system. Particularly in the case of the oldest objects that formed in the solar system - Ca-Al rich inclusions (CAls) - this view is confirm the hypothesis that a nearby supernova event facilitated or even triggered solar system formation. We present Hf isotope data for bulk meteorites, terrestrial materials and CAIs, for the first time including the low-abundance isotope Hf-174 (similar to 0.16%). This rare isotope was likely produced during explosive 0/Ne shell burning in massive stars (i.e., the classical p-process), and therefore its abundance potentially provides a sensitive tracer for putative heterogeneities within the solar system that were introduced by supernova ejecta. For CAls and one LL chondrite, also complementary W isotope data are reported for the same sample cuts. Once corrected for small neutron capture effects, different chondrite groups, eucrites, a silicate inclusion of a JAB iron meteorite, and terrestrial materials display homogeneous Hf isotope compositions including 174Hf. Hafnium-174 was thus uniformly distributed in the inner solar system when planetesimals formed at the <50 ppm level. This finding is in good agreement with the evidently homogeneous distributions of p-process isotopes W-180, Os-184 and possibly Pt-180 between different iron meteorite groups. In contrast to bulk meteorite samples, CAls show variable depletions in p-process 174Hf with respect to the inner solar system composition, and also variable r-process (or s-process) Hf and W contributions. Based on combined Hf and W isotope compositions, we show that CAls sampled at least one component in which the proportion of r- and s-process derived Hf and W deviates from that of supernova ejecta. The Hf and W isotope anomalies in CAls are therefore best explained by selective processing of presolar carrier phases prior to CAI formation, and not by a late injection of supernova materials. Likewise, other isotope anomalies in additional elements in CAIs relative to the bulk solar system may reflect the same process. The isotopic heterogeneities between the first refractory condensates may have been eradicated partially during CAI formation, because W isotope anomalies in CAls appear to decrease with increasing W concentrations as inferred from time -integrated (182)w/W-184. Importantly, the Lu-178-Hf-176 and Hf-182-W-182 chronometers are not significantly affected by nucleosynthetic heterogeneity of Hf isotopes in bulk meteorites, but may be affected in CAls. (C) 2016 Elsevier B.V. All rights reserved