Linear logic as a tool for planning under temporal uncertainty

AbstractThe typical AI problem is that of making a plan of the actions to be performed by a controller so that it could get into a set of final situations, if it started with a certain initial situation.The plans, and related winning strategies, happen to be finite in the case of a finite number of states and a finite number of instant actions.The situation becomes much more complex when we deal with planning under temporal uncertainty caused by actions with delayed effects.Here we introduce a tree-based formalism to express plans, or winning strategies, in finite state systems in which actions may have quantitatively delayed effects. Since the delays are non-deterministic and continuous, we need an infinite branching to display all possible delays. Nevertheless, under reasonable assumptions, we show that infinite winning strategies which may arise in this context can be captured by finite plans.The above planning problem is specified in logical terms within a Horn fragment of affine logic. Among other things, the advantage of linear logic approach is that we can easily capture ‘preemptive/anticipative’ plans (in which a new action β may be taken at some moment within the running time of an action α being carried out, in order to be prepared before completion of action α).In this paper we propose a comprehensive and adequate logical model of strong planning under temporal uncertainty which addresses infinity concerns. In particular, we establish a direct correspondence between linear logic proofs and plans, or winning strategies, for the actions with quantitative delayed effects

Neoglycoconjugates Derived from Deoxynojirimycin as Possible Therapeutic Agents for Cystic Fibrosis Lung Disease, by Modulation of the Sphingolipid Metabolism

The identification and development of novel and more efficient anti-inflammatory drugs for management of Cystic Fibrosis (CF) airway disease remains a compelling need. Sphingolipids (SLs) play an important regulatory role in CF due to their function in pulmonary infections and inflammation. Given the emerging importance of SLs in much pathology, novel drugs are continuously developed to selectively target different enzymes involved in SL metabolism. Iminosugars disclose offer exciting and innovative opportunities for therapeutic agent discovery. Miglustat, the most popular iminosugar, has an anti-inflammatory effect in CF models through inhibiting non-lysosomal-\u3b2-glucosidase 2 (GBA2). A small library of neoglycoconjugates with an adamantane mojety (AMP-DNJ), characterized by differences in the length of the alkyl chain between the iminosugar and AMP, has been synthesized from the lead iminosugar deoxynojirimycin (DNJ) (Ardes-Guisot, 2011). This study was hence aimed to test the effect of these AMP-DNJ derivatives on the inflammatory response to P. aeruginosa in CF bronchial epithelial cells. Our original findings demonstrate that these AMP-DNJ derivatives reduce IL-8 mRNA expression in CF bronchial cells infected by P. aeruginosa at nanomolar concentrations. The selectivity towards \u3b2 glucosidase seems to be modulated by variation of the length of the chain linking the iminosugar and AMP, which are key motifs for the therapeutic activity of these compounds. Our results further support the use of SL metabolism modulators for treating CF lung inflammation, thus providing useful hints on relevant targets and chemical structures that may be regarded as starting points for a drug discovery campaign

β‐Mannosylation through O‐Alkylation of Anomeric Cesium Alkoxides: Mechanistic Studies and Synthesis of the Hexasaccharide Core of Complex Fucosylated N‐Linked Glycans

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154903/1/ejoc202000313.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154903/2/ejoc202000313-sup-0001-SupMat.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154903/3/ejoc202000313_am.pd

Synthesis, self-assembly, and immunological activity of α-galactose-functionalized dendron–lipid amphiphiles

Nanoassemblies presenting multivalent displays of biologically active carbohydrates are of significant interest for a wide array of biomedical applications ranging from drug delivery to immunotherapy. In this study, glycodendron–lipid hybrids were developed as a new and tunable class of dendritic amphiphiles. A modular synthesis was used to prepare dendron–lipid hybrids comprising distearylglycerol and 0 through 4th generation polyester dendrons with peripheral protected amines. Following deprotection of the amines, an isothiocyanate derivative of C-linked α-galactose (α-Gal) was conjugated to the dendron peripheries, affording amphiphiles with 1 to 16 α-Gal moieties. Self-assembly in water through a solvent exchange process resulted in vesicles for the 0 through 2nd generation systems and micelles for the 3rd and 4th generation systems. The critical aggregation concentrations decreased with increasing dendron generation, suggesting that the effects of increasing molar mass dominated over the effects of increasing the hydrophilic weight fraction. The binding of the assemblies to Griffonia simplicifolia Lectin I (GSL 1), a protein with specificity for α-Gal was studied by quantifying the binding of fluorescently labeled assemblies to GSL 1-coated beads. It was found that binding was enhanced for amphiphiles containing higher generation dendrons. Despite their substantial structural differences with the natural ligands for the CD1d receptor, the glycodendron–lipid hybrids were capable of stimulating invariant natural killer T (iNKT) cells, a class of innate-like T cells that recognize lipid and glycolipid antigens presented by CD1d and that are implicated in a wide range of diseases and conditions including but not limited to infectious diseases, diabetes and cancer

Programmation logique (non-commutativité et polarisation)

PARIS13-BU Sciences (930792102) / SudocSudocFranceF

Ordinals II : some applications and a functorial approach

In the first part of this work we present some complements on ordinals or some usual applications of ordinals: in the section 2, we define a system of ordinal notations for ordinals lesser than Gamma_0; the section 3 is devoted to a simple and direct connection between Kruskal's theorem and Gamma_0; in the section 4, we show how use ordinals for consistency proofs in proof theory (for instance the consistency of Peano arithmetic by means of transfinite induction up to epsilon_0

Cut Elimination for the Unified Logic

In the paper entitled "On the Unity of Logic", J.-Y. Girard presented a calculus, called LU, which is common to classical logic, intuitionistic logic and linear logic. The main result of Girard's paper is that each of the latter logics turns out to be a fragment of LU ; the proof relies on a cut-elimination theorem for LU, which is claimed to be more or less obvious. In fact, the proof of the cut-eliminaton theorem is somewhat intricate because of the mutual behaviour of the three different cut rules (one "linear" cut and two "classical" ones) of LU : eliminating a classical cut produces linear cuts while the elimination of a linear cut produces classical ones. In the present paper, we prove that LU enjoys cut-elimination under minimal hypotheses : a notion of degree for a formula is introduced, which depends only on the number of exponentials of the formula