The size, composition and fissioning in baboon troops (Papio ursinus Kerr, 1792)

Several baboon troops were studied during a two year study period. Sub-troop formation in troops was regularly observed and such sub-troops are defined as temporary or semi-permanent. Sub-troops are either normally or abnormally composed as far as age and sex classes are concerned. A temporary sub-troop sleeps apart from the main sub-troop, and these sub-troops reunite the following morning. A semi-permanent sub-troop separates from the main sub-troop for several days. During this period the semi-permanent sub-troop only joins the main sub-troop at sleeping places. The behaviour of certain males is prominent when sub-troops are formed. This study revealed that the baboon troop is wrongly referred to as a stable unit

An efficient sampling algorithm for Variational Monte Carlo

We propose a new algorithm for sampling the $N$-body density $|\Psi({\bf R})|^2/\int_{\mathbb{R}^{3N}} |\Psi|^2$ in the Variational Monte Carlo (VMC) framework. This algorithm is based upon a modified Ricci-Ciccotti discretization of the Langevin dynamics in the phase space $({\bf R},{\bf P})$ improved by a Metropolis acceptation/rejection step. We show through some representative numerical examples (Lithium, Fluorine and Copper atoms, and phenol molecule), that this algorithm is superior to the standard sampling algorithm based on the biased random walk (importance sampling).Comment: 23 page

A reduced model for shock and detonation waves. I. The inert case

We present a model of mesoparticles, very much in the Dissipative Particle Dynamics spirit, in which a molecule is replaced by a particle with an internal thermodynamic degree of freedom (temperature or energy). The model is shown to give quantitavely accurate results for the simulation of shock waves in a crystalline polymer, and opens the way to a reduced model of detonation waves

A reduced model for shock and detonation waves. II. The reactive case

We present a mesoscopic model for reactive shock waves, which extends a previous model proposed in [G. Stoltz, Europhys. Lett. 76 (2006), 849]. A complex molecule (or a group of molecules) is replaced by a single mesoparticle, evolving according to some Dissipative Particle Dynamics. Chemical reactions can be handled in a mean way by considering an additional variable per particle describing a rate of reaction. The evolution of this rate is governed by the kinetics of a reversible exothermic reaction. Numerical results give profiles in qualitative agreement with all-atom studies

Enantioselective Catalysis Coupled with Stereodivergent Cyclization Strategies Enables Rapid Syntheses of (+)-Limaspermidine and (+)-Kopsihainanine A

Enantioselective Pd-catalyzed allylic alkylations of dihydropyrido[1,2-a]indolone (DHPI) substrates were used to construct the C20-quaternary stereocenters of multiple monoterpene indole alkaloids. Stereodivergent Pictet–Spengler and Bischler–Napieralski cyclization/reduction cascades furnish the cis- and trans-fused azadecalin subunits present in Aspidosperma and Kopsia alkaloids, respectively, en route to highly efficient syntheses of (+)-limaspermidine and (+)-kopsihainanine A

Palladium-Catalyzed Decarboxylative Asymmetric Allylic Alkylation of 1,4-Diazepan-5-ones

We report the palladium-catalyzed asymmetric allylic alkylation of 1,4-diazepan-5-ones. This reaction proceeds smoothly to give gem-disubstituted diazepanone heterocycles bearing various functional groups in up to >99% yield and up to 95% ee. An electron-rich p-anisoyl lactam protecting group and the use of a nonpolar solvent proved crucial to obtaining high enantioselectivity in most cases. Additionally, we demonstrate the use of our methodology in the synthesis of a gem-disubstituted analogue of the FDA-approved anti-insomnia drug suvorexant

Enantioselective Synthesis of α‑Quaternary Mannich Adducts by Palladium-Catalyzed Allylic Alkylation: Total Synthesis of (+)-Sibirinine

A catalytic enantioselective method for the synthesis of α-quaternary Mannich-type products is reported. The two-step sequence of (1) Mannich reaction followed by (2) decarboxylative enantioselective allylic alkylation serves as a novel strategy to in effect access asymmetric Mannich-type products of “thermodynamic” enolates of substrates possessing additional enolizable positions and acidic protons. Palladium-catalyzed decarboxylative allylic alkylation enables the enantioselective synthesis of five-, six-, and seven-membered ketone, lactam, and other heterocyclic systems. The mild reaction conditions are notable given the acidic free N–H groups and high functional group tolerance in each of the substrates. The utility of this method is highlighted in the first total synthesis of (+)-sibirinine