Isolation and structure elucidation of a neuropeptide from three species of Namib Desert tenebrionid beetles

The corpora cardiaca of three Namib Desert beetles, Onymacris plana, O. rugatipennis and Physadesmia globosa (family Tenebrionidae), contain hyperlipaemic and/or hypertrehalosaemic factors as shown by heterologous bioassays in migratory locusts and American cockroaches. The compounds have been isolated by reversed-phase high performance liquid chromatography from the three species. The retention times of the compounds for all three species were identical. Amino acid composition data, in combination with determination of the primary structure by pulsed-liquid phase sequencing employing Edman chemistry after enzymically deblocking the N-terminal pyroglutamate residue, reveals an identical octapeptide for the three investigated species: pGlu-Leu-Asn-Phe-Ser-Pro-Asn-TrpNH2. This peptide, code-named Tem-HrTH, is a member of the large adipokinetic hormone/red pigment-concentrating hormone family and was previously found in two other tenebrionid beetles which are only very distantly related to the Namib beetles. Thus, it appears that during evolution of tenebrionid beetles only one AKH/RPCH-family peptide was recruited

Insect neuropeptides regulating substrate mobilisation

Insect flight muscles perform their work completely aerobically, and working flight muscles are known to be the most metabolically active tissue in nature with respect to oxygen uptake. Various substrates can be oxidised and utilised as fuels for flight. Insects such as Diptera and Hymenoptera power their flight muscles by the breakdown of carbohydrates, whereas lipids are the predominant fuel for the contracting flight muscles of Lepidoptera and Orthoptera during long-distance flight. The amino acid proline can also be used as a substrate for flight, especially in tsetse flies and beetles (Colorado potato beetle, blister beetles, certain dung beetles). Neuropeptides from the corpus cardiacum are well-known to be responsible for carbohydrate and lipid mobilisation from the fat body. In this short overview, we show that peptides belonging to the large adipokinetic hormone/red pigment-concentrating hormone family are also thought to be the chemical messengers for initiating proline homeostasis. The peptides isolated and sequenced so far from glands of beetles from the genera Pachnoda, Scarabaeus and Onitis all have a tyrosine residue (at position 2 or 4) and seem to be related to each other

Unilaterally removing implicit subsidies for maritime fuels

Many academics and policymakers agree that implicit tax subsidies for maritime fuels — which are currently granted around the world — are inefficient, but that their abolishment requires a unanimous international agreement. Such an agreement is deemed indispensable because any unilateral action would be impossible due to massive tax competition in this industry, competitiveness effects and the legal limits on regulating an industry operating mostly in international waters, thus outside of any state’s jurisdiction. However, an international agreement to solve these problems has proven impossible to reach, thus resulting in the conservation of the status quo. To break this dead

Large-scale log analysis of digital reading

In this paper, we address daily reading practices of the general public in Russia analyzing 10 months of log data from the commercial ebook site Bookmate. We study different reading characteristics with ebooks, i.e. the reading volume and preferences, reading schedule, reading speed and reading style (including parallel reading patterns and book abandonment rates), with respect to reader gender, book length and genre of the book. We find that book genres impact certain reading behaviors, while gender differences or book length seem to play less of a role in ebook reading. Parallel book reading and book abandonment occur very frequently, possibly pointing towards changing reading behaviors in the ebook environment. The obtained insights demonstrate the high potential of log analysis for book reading studies. Copyright © 2016 by Association for Information Science and Technolog