Biography: Professor Moshe Rubin

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Strategy Logic with Imperfect Information

We introduce an extension of Strategy Logic for the imperfect-information setting, called SLii, and study its model-checking problem. As this logic naturally captures multi-player games with imperfect information, the problem turns out to be undecidable. We introduce a syntactical class of "hierarchical instances" for which, intuitively, as one goes down the syntactic tree of the formula, strategy quantifications are concerned with finer observations of the model. We prove that model-checking SLii restricted to hierarchical instances is decidable. This result, because it allows for complex patterns of existential and universal quantification on strategies, greatly generalises previous ones, such as decidability of multi-player games with imperfect information and hierarchical observations, and decidability of distributed synthesis for hierarchical systems. To establish the decidability result, we introduce and study QCTL*ii, an extension of QCTL* (itself an extension of CTL* with second-order quantification over atomic propositions) by parameterising its quantifiers with observations. The simple syntax of QCTL* ii allows us to provide a conceptually neat reduction of SLii to QCTL*ii that separates concerns, allowing one to forget about strategies and players and focus solely on second-order quantification. While the model-checking problem of QCTL*ii is, in general, undecidable, we identify a syntactic fragment of hierarchical formulas and prove, using an automata-theoretic approach, that it is decidable. The decidability result for SLii follows since the reduction maps hierarchical instances of SLii to hierarchical formulas of QCTL*ii

Direct visualization of lipid aggregates in native human bile by light- and cryo-transmission electron-microscopy

AbstractThe evolution of microstructures present in human gallbladder and hepatic bile was observed simultaneously by video-enhanced light microscopy (VELM) and transmission electron microscopy of vitrified specimens (cryo-TEM), as a function of time after withdrawal from patients. Fresh centrifuged gallbladder bile samples contained small (6 nm) spherical micelles in coexistence with vesicles (40 nm). Out of the seven bile samples investigated four contained, in addition, two types of elongated aggregates that have not been previously described. Uncentrifuged gallbladder bile also contained a mixture of ribbon- and plate-like crystals seen by VELM, but not by cryo-TEM. In aged (3–6-week-old) gallbladder bile samples VELM also revealed spiral and helical crystal structures. No such crystals were present in hepatic bile samples, although microcrystals, not observable by VELM were seen by cryo-TEM in addition to micelles and vesicles. The similarity of these observations to those observed in bile models lends strong support for the validity of the model systems. Furthermore, the presence of microcrystals in hepatic bile samples, apparently devoid of crystals by light microscopy, indicates that under certain conditions the common criterion of ‘nueleation time’ (NT), based on light microscopy, does not represent the real time of nucleation. In the human bile samples investigated in this study the dissociation between NT and the time of observation of microcrystals was seen in hepatic but not in gallbladder bile samples. Hence, crystal growth may be rate limiting only in dilute biles

Strategy Logic with Imperfect Information

We introduce an extension of Strategy Logic for the imperfect-information setting, called SLii, and study its model-checking problem. As this logic naturally captures multi-player games with imperfect information, this problem is undecidable; but we introduce a syntactical class of "hierarchical instances" for which, intuitively, as one goes down the syntactic tree of the formula, strategy quantifications are concerned with finer observations of the model, and we prove that model-checking SLii restricted to hierarchical instances is decidable. To establish this result we go through QCTL, an intermediary, "low-level" logic much more adapted to automata techniques. QCTL is an extension of CTL with second-order quantification over atomic propositions. We extend it to the imperfect information setting by parameterising second-order quantifiers with observations. While the model-checking problem of QCTLii is, in general, undecidable, we identify a syntactic fragment of hierarchical formulas and prove, using an automata-theoretic approach, that it is decidable. We apply our result to solve complex strategic problems in the imperfect-information setting. We first show that the existence of Nash equilibria for deterministic strategies is decidable in games with hierarchical information. We also introduce distributed rational synthesis, a generalisation of rational synthesis to the imperfect-information setting. Because it can easily be expressed in our logic, our main result provides solution to this problem in the case of hierarchical information.Comment: arXiv admin note: text overlap with arXiv:1805.1259

Diagnosing celiac disease by video capsule endoscopy (VCE) when esophogastroduodenoscopy (EGD) and biopsy is unable to provide a diagnosis: a case series

Video capsule endoscopy (VCE) is mainly used to evaluate patients with celiac disease in whom their course after diagnosis has been unfavorable and the diagnosis of adenocarcinoma, lymphoma or refractory celiac disease is entertained, but it has been suggested that VCE could replace esophagogastroduodenoscopy (EGD) and biopsy under certain circumstances. We report a single center case series of 8 patients with suspected celiac disease who were diagnosed by VCE. EGD and biopsy had been performed in 4 patients resulting in a negative biopsy, declined by 2, and contraindicated in 2 due to hemophilia and von Willebrand disease. In all patients, mucosal changes of scalloping, mucosal mosaicism and reduced folds were seen in either the duodenum or jejunum on VCE. Follow-up in 7 patients demonstrated improvement in either their serological abnormalities or their presenting clinical features on a gluten-free diet. Our case series demonstrates that VCE and the visualization of the characteristic mucosal changes of villous atrophy may replace biopsy as the mode of diagnosis when EGD is either declined or contraindicated, or when duodenal biopsies are negative and there remains a high index of suspicion. Further study is needed to clarify the role and cost of diagnosing celiac disease with VCE

Vegetation history and climatic fluctuations on a transect along the Dead Sea west shore and impact on past societies over the last 3500 years.

This study represents the vegetation history of the last 3500 years and conducts an analysis of the climatic fluctuations on a 75 km long transect on the western Dead Sea shore. Palynological and sedimentological data are available from six cores near Mount Sedom, Ein Boqueq, and Ein Gedi and from outcrops near Ze'elim and Ein Feshkha. The comparison of the pollen data with the lake levels shows synchronous trends. During the Middle Bronze Age, Iron Age and Hellenistic to Byzantine Period the high lake level of the Dead Sea signals an increase in precipitation. Contemporaneously, values of cultivated plants indicate an increase in agriculture. Lake level is low during the Late Bronze Age, within the Iron Age and at the end of the Byzantine period, indicating dry periods when all pds show a decrease of cultivated plants. Forest regeneration led by drought-resistant pines is observed in all pollen diagrams (pds) following the agricultural decline in the Byzantine period and, in the pds near Ein Boqeq, Ze'elim and Ein Feshkha, during the late Iron Age. The modern vegetation gradient is reflected in the palaeo-records: a stronger expansion of Mediterranean vegetation and cultivated plants in the northern sites is recognisable

Epithelioid Angiosarcoma of the Small Intestine After Occupational Exposure to Radiation and Polyvinyl Chloride: A case Report and Review of Literature

Angiosarcomas represent 1–2% of soft tissue sarcomas and most frequently occur in the subcutis. They may affect internal organs, such as the heart, liver, and spleen, and only rarely do they emerge in the gastrointestinal tract. The association between angiosarcomas and certain toxic chemical substances or previous external-beam radiation therapy is well documented