Ancient DNA from a 2,500-year-old Caribbean fossil places an extinct bird (Caracara creightoni) in a phylogenetic context.

Since the late Pleistocene humans have caused the extinction of species across our planet. Placing these extinct species in the tree of life with genetic data is essential to understanding the ecological and evolutionary implications of these losses. While ancient DNA (aDNA) techniques have advanced rapidly in recent decades, aDNA from tropical species, especially birds, has been historically difficult to obtain, leaving a gap in our knowledge of the extinction processes that have influenced current distributions and biodiversity.

Tropylium ion mediated α-cyanation of amines.

Tropylium ion mediated α-cyanation of amines is described. Even in the presence of KCN, tropylium ion is capable of oxidizing various amine substrates, and the resulting iminium ions undergo salt metathesis with cyanide ion to produce aminonitriles. The byproducts of this transformation are simply cycloheptatriene, a volatile hydrocarbon, and water-soluble potassium tetrafluoroborate.

Multicatalytic synthesis of complex tetrahydrofurans involving bismuth(III) triflate catalyzed intramolecular hydroalkoxylation of unactivated olefins.

A multicatalytic synthesis of complex tetrahydrofurans has been developed involving a Bi(OTf)(3)-catalyzed nucleophilic addition/hydroalkoxylation sequence. Complex tetrahydrofuranyl products may be formed rapidly in high yield and with good diastereoselectivity. The demonstrated scope of hydroalkoxylation has also been expanded to include substrates bearing useful functional handles including carboxylate ester, olefin, nitrile, and nitro groups.

Why are a(3) ions rarely observed?

It has been determined experimentally that a(3) ions are generally not observed in the tandem mass spectroscopic (MS/MS) spectra of b(3) ions. This is in contrast to other b(n) ions, which often have the corresponding a(n) ion as the base peak in their MS/MS spectra. Although this might suggest a different structure for b(3) ions compared to that of other b(n) ions, theoretical calculations indicate the conventional oxazolone structure to be the lowest energy structure for the b(3) ion of AAAAR, as it is for other b(n) ions of this peptide.

Heroin-induced locomotor activity and conditioned place preference in C57BL/6J and 129P3/J mice.

Differences in the locomotor stimulating and rewarding properties of drugs of abuse have been described in several inbred strains of mice, and comparisons of inbred strains with differing responses to drugs of abuse may provide crucial insight into the question of individual vulnerability to the effects of drugs of abuse. The present study was designed to examine the rewarding and locomotor-stimulating effects of heroin in C57BL/6J and 129P3/J mice. Heroin produced a robust dose-dependent locomotor stimulation in both strains.