On the incorporation of adversarial reasoning in course of action analysis and resource allocation

Course of Action analysis and Resource Management are concerned with the allocation of resources over time to effect desired actions as a result of the perceived situation awareness. Decision Support Systems provide automated recommended courses of action to decision makers, considering relevant resource capabilities and constraints. Incorporating potential adversary actions and reactions to the current course of action decision (and the resources effecting the actions) in the decision making process will make the decision support system more robust and increase confidence that the recommended decisions are appropriate responses to the unfolding situations. We discuss research results from the inclusion of possible adversary actions and reactions into the course of action/resource allocation decision making framework. The overall decision problem is formulated as a multi-stage mathematical program. As the problem is NP-hard, an heuristic is developed through a natural problem decomposition. Simulated results show the effectiveness of the heuristic in producing good-quality solutions in an efficient manner.     

Influence of atmospheric turbulence on states of light carrying orbital angular momentum

We have experimentally studied the degradation of mode purity for light beams carrying orbital angular momentum (OAM) propagating through simulated atmospheric turbulence. The turbulence is modeled as a randomly varying phase aberration, which obeys statistics postulated by Kolmogorov turbulence theory. We introduce this simulated turbulence through the use of a phase-only spatial light modulator. Once the turbulence is introduced, the degradation in mode quality results in crosstalk between OAM modes. We study this crosstalk in OAM for 11 modes, showing that turbulence uniformly degrades the purity of all the modes within this range, irrespective of mode number.     

Atypical “Masked” Frustrated Lewis Pair Character in a Geminal-Linked Phosphine-Borane

We report the synthesis and reactivity of the geminal-linked fluorene-derived P/B frustrated Lewis pair (FLP) ⁱPr₂P(C₁₃H₈)BCy₂ ( 1 ). Compound 1 displays anomalous behavior towards small molecules, acting as a “masked” FLP. This behavior stems from significant polarization of the B−C(fluorene) bond in 1 , as identified by density functional theory (DFT) computations. We exploit this B−C bond polarity through reactions with PhPCl₂, H₃N ⋅ BH₃, and ⁱPrNH₂, demonstrating P−Cl and N−H bond activation, respectively.     

Frustrated Lewis Pair Adduct of Atomic P(−1) as a Source of Phosphinidenes (PR), Diphosphorus (P2), and Indium Phosphide

We report phosphinidenes (PR) stabilized by an intramolecular frustrated Lewis pair (FLP) chelate. These adducts include the parent phosphinidene, PH, which is accessed via thermolysis of coordinated HPCO. The reported FLP-PH species acts as a springboard to other phosphorus-containing compounds, such as FLP-adducts of diphosphorus (P₂) and InP₃. Our new adducts participate in thermal- or light-induced phosphinidene elimination (of both PH and PR, R=organic group), transfer P₂ units to an organic substrate, and yield the useful semiconductor InP at only 110 °C from solution.     

Optimal navigation of a smart active particle: directional and distance sensing

The European Physical Journal E - This work aims at finding optimal navigation policies for thin, deformable microswimmers that progress in a viscous fluid by propagating a sinusoidal undulation...     

Lewis Acid Supported Nickel Nitrenoids

Metalation of the polynucleating ligand ^F,tbsLH₆ (1,3,5-C₆H₉(NC₆H₃−4-F−2-NSiMe₂^tBu)₃) with two equivalents of Zn(N(SiMe₃)₂)₂ affords the dinuclear product (^F,tbsLH₂)Zn₂ ( 1 ), which can be further deprotonated to yield (^F,tbsL)Zn₂Li₂(OEt₂)₄ ( 2 ). Transmetalation of 2 with NiCl₂(py)₂ yields the heterometallic, trinuclear cluster (^F,tbsL)Zn₂Ni(py) ( 3 ). Reduction of 3 with KC₈ affords [KC₂₂₂][(^F,tbsL)Zn₂Ni] ( 4 ) which features a monovalent Ni centre. Addition of 1-adamantyl azide to 4 generates the bridging μ³-nitrenoid adduct [K(THF)₃][(^F,tbsL)Zn₂Ni(μ³-NAd)] ( 5 ). EPR spectroscopy reveals that the anionic cluster possesses a doublet ground state (S = ). Cyclic voltammetry of 5 reveals two fully reversible redox events. The dianionic nitrenoid [K₂(THF)₉][(^F,tbsL)Zn₂Ni(μ³-NAd)] ( 6 ) was isolated and characterized while the neutral redox isomer was observed to undergo both intra- and intermolecular H-atom abstraction processes. Ni K-edge XAS studies suggest a divalent oxidation state for the Ni centres in both the monoanionic and dianionic [Zn₂Ni] nitrenoid complexes. However, DFT analysis suggests Ni-borne oxidation for 5 .     

Fluorogenic Photo-Crosslinking of Glycan-Binding Protein Recognition Using a Fluorinated Azido-Coumarin Fucoside

Glycan recognition by glycan-binding proteins is central to the biology of all living organisms. The efficient capture and characterization of relatively weak non-covalent interactions remains an important challenge in various fields of research. Photoaffinity labeling strategies can create covalent bonds between interacting partners, and photoactive scaffolds such as benzophenone, diazirines and aryl azides have proved widely useful. Since their first introduction, relatively few improvements have been advanced and products of photoaffinity labeling remain difficult to detect. We report a fluorinated azido-coumarin scaffold which enables photolabeling under fast and mild activation, and which can leave a fluorescent tag on crosslinked species. Coupling this scaffold to an α-fucoside, we demonstrate fluorogenic photolabeling of glycan-protein interactions over a wide range of affinities. We expect this strategy to be broadly applicable to other chromophores and we envision that such “fluoro-crosslinkers” could become important tools for the traceable capture of non-covalent binding events.     

Nanoparticle-Decorated Biomimetic Extracellular Matrix for Cell Nanoencapsulation and Regulation

Cell encapsulation has been studied for various applications ranging from cell transplantation to biological production. However, current encapsulation technologies focus on cell protection rather than cell regulation that is essential to most if not all cell-based applications. Here we report a method for cell nanoencapsulation and regulation using an ultrathin biomimetic extracellular matrix as a cell nanocapsule to carry nanoparticles (CN²). This method allows high-capacity nanoparticle retention at the vicinity of cell surfaces. The encapsulated cells maintain high viability and normal metabolism. When gold nanoparticles (AuNPs) are used as a model to decorate the nanocapsule, light irradiation transiently increases the temperature, leading to the activation of the heat shock protein 70 (HSP70) promoter and the regulation of reporter gene expression. As the biomimetic nanocapsule can be decorated with any or multiple NPs, CN² is a promising platform for advancing cell-based applications.