The source and the age of the soil organic matter of Anthrosols in SW Norway

Recent investigations showed that humus‑rich topsoil’s around the Baltic Sea have been formed by the application of pyrogenic organic matter (Acksel et al., 2016, Geoderma Reg. 7, 187–200) and organic materials (e.g. animal manure, organic waste) linked with human activity and, consequently, these soils were classified as Anthrosols (Acksel et al., 2017 (submitted)). Such humus‑rich topsoil’s, which were strongly influenced by anthropogenic activities and classified as plaggic Anthrosols, were described in SW Norway (Schnepel et al., 2014, J. Plant Nutr. Soil Sci., 177 (4), 638–645.). However, the source and the formation time of the Anthrosols in Norway have not been investigated in detail. Therefore, we characterized the soil organic matter composition by pyrolysis-field ionisation-mass spectrometry (Py-FIMS), benzene polycarboxylic acids (BPCA) determination, examined the source of the SOM by isotopic signatures (d34S) and estimated the age of the SOM by 14C AMS dating in order to find out the beginning of Anthrosol formation. Py-FIMS revealed high portions of sterols and fatty acids, indicating inputs of manure, similar to plaggic Anthrosols in NW Germany. The BC portions (≈ 19 % BC of Corg) were similar to various Anthrosols (≈ 25 % BC of Corg) and Chernozems (≈ 13 % BC of Corg) worldwide and indicated an input of combustion residues to soils by early fire events. The d34S isotope signature of the SOM ranged from 10 to 13.4 ‰ at the islands and 10.6 to 15.2 in the Jaeren region of SW Norway, corresponded to the Anthrosols in the Baltic Sea region (Median: d34S = 11.5 ‰) and indicated an input of marine biomass (d34S of seaweed = 20 ‰). All these results complemented the study of Schnepel et al. (2014) and provided strong evidence that these soils were formed by human activities. Ongoing analyses of 14C ages from these soils enable to estimate the timing of the soil formation and link it to settlement history

Reflecting on loss in Papua New Guinea

This article takes up the conundrum of conducting anthropological fieldwork with people who claim that they have 'lost their culture,' as is the case with Suau people in the Massim region of Papua New Guinea. But rather than claiming culture loss as a process of dispossession, Suau claim it as a consequence of their own attempts to engage with colonial interests. Suau appear to have responded to missionization and their close proximity to the colonial-era capital by jettisoning many of the practices characteristic of Massim societies, now identified as 'kastom.' The rejection of kastom in order to facilitate their relations with Europeans during colonialism, followed by the mourning for kastom after independence, both invite consideration of a kind of reflexivity that requires action based on the presumed perspective of another

Fluorescence Dequenching Makes Haem-Free Soluble Guanylate Cyclase Detectable in Living Cells

In cardiovascular disease, the protective NO/sGC/cGMP signalling-pathway is impaired due to a decreased pool of NO-sensitive haem-containing sGC accompanied by a reciprocal increase in NO-insensitive haem-free sGC. However, no direct method to detect cellular haem-free sGC other than its activation by the new therapeutic class of haem mimetics, such as BAY 58-2667, is available. Here we show that fluorescence dequenching, based on the interaction of the optical active prosthetic haem group and the attached biarsenical fluorophor FlAsH can be used to detect changes in cellular sGC haem status. The partly overlap of the emission spectrum of haem and FlAsH allows energy transfer from the fluorophore to the haem which reduces the intensity of FlAsH fluorescence. Loss of the prosthetic group, e.g. by oxidative stress or by replacement with the haem mimetic BAY 58-2667, prevented the energy transfer resulting in increased fluorescence. Haem loss was corroborated by an observed decrease in NO-induced sGC activity, reduced sGC protein levels, and an increased effect of BAY 58-2667. The use of a haem-free sGC mutant and a biarsenical dye that was not quenched by haem as controls further validated that the increase in fluorescence was due to the loss of the prosthetic haem group. The present approach is based on the cellular expression of an engineered sGC variant limiting is applicability to recombinant expression systems. Nevertheless, it allows to monitor sGC's redox regulation in living cells and future enhancements might be able to extend this approach to in vivo conditions

Accessing stable magnesium acyl compounds : reductive cleavage of esters by magnesium(I) dimers

C.J. and A.S. thank the Australian Research Council for financial support. C.J. also thanks the U.S. Air Force Asian Office of Aerospace Research and Development (grant FA2386-14-1-4043).The first examples of magnesium acyls, [(Nacnac)Mg{μ-C(Ph)O}(μ-OR)Mg(Nacnac)] (R = Me, But or Ph; Nacnac = [HC(MeCNAr)2]-; Ar = C6H2Me3-2,4,6 (MesNacnac), C6H3Et2-2,6 (DepNacnac), C6H3Pri2-2,6 (DipNacnac)), have been prepared by reductive cleavage of a series of esters using dimeric magnesium(I) reducing agents, [{(Nacnac)Mg}2]. Crystallographic studies reveal the complexes to be dimeric, being bridged by both phenyl-acyl and alkoxide/aryloxide fragments. The crystal structures, combined with results of spectroscopic and computational studies suggest that the nature of the acyl ligands within these complexes should be viewed as lying somewhere between anionic umpolung acyl and oxo-carbene. However, reactions of the acyl complexes with a variety of organic electrophiles did not provide evidence of umpolung acyl reactivity. A number of attempts to prepare alkoxide free magnesium acyls were carried out, and while these were unsuccessful, they did lead to unusual products, the crystallographic and spectroscopic details of which are discussed.PostprintPeer reviewe

Receptor guanylyl cyclase (RGC) family (version 2020.3) in the IUPHAR/BPS Guide to Pharmacology Database

The mammalian genome encodes seven guanylyl cyclases, GC-A to GC-G, that are homodimeric transmembrane receptors activated by a diverse range of endogenous ligands. These enzymes convert guanosine-5'-triphosphate to the intracellular second messenger cyclic guanosine-3',5'-monophosphate (cyclic GMP). GC-A, GC-B and GC-C are expressed predominantly in the cardiovascular system, skeletal system and intestinal epithelium, respectively. GC-D and GC-G are found in the olfactory neuropepithelium and Grueneberg ganglion of rodents, respectively. GC-E and GC-F are expressed in retinal photoreceptors

Receptor guanylyl cyclase (RGC) family in GtoPdb v.2023.1

The mammalian genome encodes seven guanylyl cyclases, GC-A to GC-G, that are homodimeric transmembrane receptors activated by a diverse range of endogenous ligands. These enzymes convert guanosine-5'-triphosphate to the intracellular second messenger cyclic guanosine-3',5'-monophosphate (cyclic GMP). GC-A, GC-B and GC-C are expressed predominantly in the cardiovascular system, skeletal system and intestinal epithelium, respectively. GC-D and GC-G are found in the olfactory neuropepithelium and Grueneberg ganglion of rodents, respectively. GC-E and GC-F are expressed in retinal photoreceptors