Trophic niche and diet composition of the northernmost population of the Mediterranean horseshoe bat (Rhinolophus euryale) with conservation implications

Mammal Research - The diet of Rhinolophus euryale was studied in southeastern Slovakia by an analysis of faeces collected from netted bats. Prey availability was studied using light traps, counting...     

Time-Resolved Fluorescence in Lipid Bilayers: Selected Applications and Advantages over Steady State

Fluorescence methods are versatile tools for obtaining dynamic and topological information about biomembranes because the molecular interactions taking place in lipid membranes frequently occur on the same timescale as fluorescence emission. The fluorescence intensity decay, in particular, is a powerful reporter of the molecular environment of a fluorophore. The fluorescence lifetime can be sensitive to the local polarity, hydration, viscosity, and/or presence of fluorescence quenchers/energy acceptors within several nanometers of the vicinity of a fluorophore. Illustrative examples of how time-resolved fluorescence measurements can provide more valuable and detailed information about a system than the time-integrated (steady-state) approach will be presented in this review: 1), determination of membrane polarity and mobility using time-dependent spectral shifts; 2), identification of submicroscopic domains by fluorescence lifetime imaging microscopy; 3), elucidation of membrane leakage mechanisms from dye self-quenching assays; and 4), evaluation of nanodomain sizes by time-resolved Förster resonance energy transfer measurements.     

An insect boring in an Early Cretaceous wood from Bornholm,Denmark

Abstract

An insect boring of unique shape is described from a lignitic layer within the Early Cretaceous (Berriasian) Skyttegård Member of the Rabekke Formation on Bornholm. Morphologically it cannot be compared to any modern or fossil wood borings, although some structures are reminiscent of Scolytidae, Platypodidae and Lymexylonidae. Most probably, however, the tracemaker was a female fungus-farming beetle, thus producing an agrichnion.     

Peroxidase activity and isoenzyme patterns in wheat during ontogenesis

Protein content, total and specific peroxidase activity and isoperoxidase patterns were determined in crude protein preparations from individual parts of field-grown wheat (Triticum aestivum L., cv. Jubilar). Protein content in roots, leaves, and stalks increased at the beginning of ontogenesis and then decreased from 6th, 9th, and 10th development phase (according to Feekes), respectively. Steady increase of the protein content in the ears was observed. Highest peroxidase activity was found in the roots; it diminished from the onset of ontogenesis till maturity of the plants. In the leaves and stalks a slight decrease of peroxidase activity till the 10th development phase and then an increase till maturity was found. The ears exhibited a gradual increase of peroxidase activity. The course of specific peroxidase activity was found to be very similar to that of total activity. Isoperoxidase patterns did not change significantly. In the leaves, a decrease of activity of C₄ and C₅ isoperoxidases was recorded. In the stalks, C l isoenzyme emerged at the end of ontogenesis. A gradual increase of A₁ and A₅ isoperoxidase intensity took place both in the leaves and stalks.     

Synthesis and biological evaluation of naphthoquinone-coumarin conjugates as topoisomerase II inhibitors

Based on previous Topoisomerase II docking studies of naphthoquinone derivatives, a series of naphthoquinone-coumarin conjugates was synthesized through a multicomponent reaction from aromatic aldehydes, 4-hydroxycoumarin and 2-hydroxynaphthoquinone. The hybrid structures were evaluated against the α isoform of human topoisomerase II (hTopoIIα), Escherichia coli DNA Gyrase and E. coli Topoisomerase I. All tested compounds inhibited the hTopoIIα-mediated relaxation of negatively supercoiled circular DNA in the low micromolar range. This inhibition was specific since neither DNA Gyrase nor Topoisomerase I were affected. Cleavage assays pointed out that naphthoquinone-coumarins act by catalytically inhibiting hTopoIIα. ATPase assays and molecular docking studies further pointed out that the mode of action is related to the hTopoIIα ATP-binding site.