Secoviridae: a proposed family of plant viruses within the order Picornavirales that combines the families Sequiviridae and Comoviridae, the unassigned genera Cheravirus and Sadwavirus, and the proposed genus Torradovirus

The order Picornavirales includes several plant viruses that are currently classified into the families Comoviridae (genera Comovirus, Fabavirus and Nepovirus) and Sequiviridae (genera Sequivirus and Waikavirus) and into the unassigned genera Cheravirus and Sadwavirus. These viruses share properties in common with other picornavirales (particle structure, positive-strand RNA genome with a polyprotein expression strategy, a common replication block including type III helicase, a 3C-like cysteine proteinase and type I RNA-dependent RNA polymerase). However, they also share unique properties that distinguish them from other picornavirales. They infect plants and use specialized proteins or protein domains to move through their host. In phylogenetic analysis based on their replication proteins, these viruses form a separate distinct lineage within the picornavirales branch. To recognize these common properties at the taxonomic level, we propose to create a new family termed “Secoviridae” to include the genera Comovirus, Fabavirus, Nepovirus, Cheravirus, Sadwavirus, Sequivirus and Waikavirus. Two newly discovered plant viruses share common properties with members of the proposed family Secoviridae but have distinct specific genomic organizations. In phylogenetic reconstructions, they form a separate sub-branch within the Secoviridae lineage. We propose to create a new genus termed Torradovirus (type species, Tomato torrado virus) and to assign this genus to the proposed family Secoviridae

Studies on Wild House Mice. VII. Prenatal Maternal Environment and Aggression

The effect of the maternal environment on intermale aggression was studied by means of embryo transfer of genetically selected aggressive (SAL) and nonaggressive wild house mice (LAL), and their reciprocal F1's, to standard (NMRI) females. No effect was found on the attack latency scores (ALS), i.e., aggression: all genotypes born and raised under natural conditions showed an ALS similar that of genotypes born and raised by NMRI females. Since previous studies on wild house mice failed to demonstrate postnatal effects on aggression, and the present results indicate the absence of prenatal maternal environmental effects on aggression, the primacy of genetic over maternal variance in the development of adult intermale aggression in wild house mice is indicated

The size and shape of the Milky Way disc and halo from M-type brown dwarfs in the BoRG survey.

We have identified 274 M-type brown dwarfs in the Hubble Space Telescope\u27s Wide Field Camera 3 pure parallel fields from the Brightest of Reionizing Galaxies (BoRG) survey for high-redshift galaxies. These are near-infrared observations with multiple lines of sight out of our Milky Way. Using these observed M-type brown dwarfs, we fitted a Galactic disc and halo model with a Markov chain Monte Carlo analysis. This model worked best with the scalelength of the disc fixed at h = 2.6 kpc. For the scaleheight of the disc, we found z0=0.29+0.02−0.019 z0=0.29−0.019+0.02 kpc and for the central number density, ρ0=0.29+0.20−0.13 ρ0=0.29−0.13+0.20 # pc−3. For the halo, we derived a flattening parameter κ = 0.45 ± 0.04 and a power-law index p = 2.4 ± 0.07. We found the fraction of M-type brown dwarfs in the local density that belong to the halo to be fh = 0.0075 +0.0025−0.0019 −0.0019+0.0025 . We found no correlation between subtype of M-dwarf and any model parameters. The total number of M-type brown dwarfs in the disc and halo was determined to be 58.2+9.81−6.70×109 58.2−6.70+9.81×109 . We found an upper limit for the fraction of M-type brown dwarfs in the halo of 7 +5−4 −4+5  per cent. The upper limit for the total Galactic disc mass in M-dwarfs is 4.34+0.73−0.5×109 4.34−0.5+0.73×109 M⊙, assuming all M-type brown dwarfs have a mass of 80 MJ

Cationic Copper Iminophosphorane Complexes as CuAAC Catalysts:A Mechanistic Study

We have combined Cu K-edge X-ray absorption spectroscopy with NMR spectroscopy (1H and 31P) to study the Cu-catalyzed azide–alkyne cycloaddition (CuAAC) reaction under operando conditions. A variety of novel, well-defined CuI iminophosphorane complexes were prepared. These ligands, based on the in situ Staudinger reduction when [Cu(PPh3)3Br] is employed, were found to be active catalysts in the CuAAC reaction. Here, we highlight recent advances in mechanistic understanding of the CuAAC reaction using spectroscopic and kinetic investigations under strict air-free and operando conditions. A mononuclear Cu triazolide intermediate is identified to be the resting state during catalysis; cyclization and protonation both have an effect on the rate of the reaction. A key finding of this study includes a novel group of highly modular CuI complexes that are active in the base-free CuAAC reaction

Electronically Asynchronous Transition States for C-N Bond Formation by Electrophilic [Co-^III(TAML)]-Nitrene Radical Complexes Involving Substrate-to-Ligand Single-Electron Transfer and a Cobalt-Centered Spin Shuttle

[Image: see text] The oxidation state of the redox noninnocent tetra-amido macrocyclic ligand (TAML) scaffold was recently shown to affect the formation of nitrene radical species on cobalt(III) upon reaction with PhI=NNs [ N. P. van Leest; J. Am. Chem. Soc.2020, 142, 552−56331846578]. For the neutral [Co(III)(TAML(sq))] complex, this leads to the doublet (S = 1/2) mono-nitrene radical species [Co(III)(TAML(q))(N(•)Ns)(Y)] (bearing an unidentified sixth ligand Y in at least the frozen state), while a triplet (S = 1) bis-nitrene radical species [Co(III)(TAML(q))(N(•)Ns)(2)](–) is generated from the anionic [Co(III)(TAML(red))](–) complex. The one-electron-reduced Fischer-type nitrene radicals (N(•)Ns(–)) are formed through single (mono-nitrene) or double (bis-nitrene) ligand-to-substrate single-electron transfer (SET). In this work, we describe the reactivity and mechanisms of these nitrene radical complexes in catalytic aziridination. We report that [Co(III)(TAML(sq))] and [Co(III)(TAML(red))](–) are both effective catalysts for chemoselective (C=C versus C–H bonds) and diastereoselective aziridination of styrene derivatives, cyclohexane, and 1-hexene under mild and even aerobic (for [Co(III)(TAML(red))](–)) conditions. Experimental (Hammett plots; [Co(III)(TAML)]-nitrene radical formation and quantification under catalytic conditions; single-turnover experiments; and tests regarding catalyst decomposition, radical inhibition, and radical trapping) in combination with computational (density functional theory (DFT), N-electron valence state perturbation theory corrected complete active space self-consistent field (NEVPT2-CASSCF)) studies reveal that [Co(III)(TAML(q))(N(•)Ns)(Y)], [Co(III)(TAML(q))(N(•)Ns)(2)](–), and [Co(III)(TAML(sq))(N(•)Ns)](–) are key electrophilic intermediates in aziridination reactions. Surprisingly, the electrophilic one-electron-reduced Fischer-type nitrene radicals do not react as would be expected for nitrene radicals (i.e., via radical addition and radical rebound). Instead, nitrene transfer proceeds through unusual electronically asynchronous transition states, in which the (partial) styrene substrate to TAML ligand (single-) electron transfer precedes C–N coupling. The actual C–N bond formation processes are best described as involving a nucleophilic attack of the nitrene (radical) lone pair at the thus (partially) formed styrene radical cation. These processes are coupled to TAML-to-cobalt and cobalt-to-nitrene single-electron transfer, effectively leading to the formation of an amido-γ-benzyl radical (NsN(–)–CH(2)–(•)CH–Ph) bound to an intermediate spin (S = 1) cobalt(III) center. Hence, the TAML moiety can be regarded to act as a transient electron acceptor, the cobalt center behaves as a spin shuttle, and the nitrene radical acts as a nucleophile. Such a mechanism was hitherto unknown for cobalt-catalyzed hypovalent group transfer and the more general transition-metal-catalyzed nitrene transfer to alkenes but is now shown to complement the known concerted and stepwise mechanisms for N-group transfer

Stable hemoglobin concentration with fecal immunochemical test at high temperatures in a Caribbean colorectal cancer screening program

Background and aims: High temperatures may reduce fecal immunochemical test (FIT) positivity and colorectal cancer (CRC) detection sensitivity. We investigated the effect of temperature on hemoglobin concentration [Hb], in the FOB Gold®. Additionally, we examined FIT pick-up, storage, return times and specimen collection. Materials and Methods: In vitro experiments with buffer containing FIT devices, inoculated with Hb-spiked stool. For 7 days, 144 samples were stored in groups of 36 at 4 °C, 22 °C, 30 °C, and 50 °C. Additionally, 54 samples were stored in groups of 18 at 34 °C, 42 °C and 50 °C for 20 h. Paired t-tests and repeated measure ANOVA assessed [Hb] change. Sixty-five screening participants completed a FIT-handling questionnaire. Results: After 7 days, mean [Hb] was stable at 30 °C (0.8 µg Hb/g;95 %CI: −1.5 to 3.1;p = 0.50). For 50 °C, mean [Hb] decreased within 2 days (−21.3 µg Hb/g;95 %CI: −30.2 to −12.5;p &lt; 0.001) and after 20 h (−63.0 µg Hb/g;95 %CI: −88.7 to −37.3;p &lt; 0.001), respectively. All other temperature categories showed significant mean [Hb] increase. Same-day FIT return was reported by 80 %. Eighty-seven percent experienced specimen collection as easy and 33 % kept the FIT refrigerated after collection. Conclusions: The FOB Gold® is suitable for CRC screening in tropical climates. Although most respondents indicated same-day sample return, we recommend avoiding FIT storage above 30 °C for longer than7 days.</p

Multiplex-detectie van plantenpathogenen

Een manier om de kosteneffectiviteit van de detectie van plantenpathogenen te verbeteren is door het tegelijkertijd detecteren van meerdere pathogenen in één monster (zgn. multiplexen). Het gebruik van de Luminex xMAP-technologie biedt een uitgelezen platform om bestaande reagentia in te zetten in een multiplex-setting

Stable hemoglobin concentration with fecal immunochemical test at high temperatures in a Caribbean colorectal cancer screening program

Background and aims: High temperatures may reduce fecal immunochemical test (FIT) positivity and colorectal cancer (CRC) detection sensitivity. We investigated the effect of temperature on hemoglobin concentration [Hb], in the FOB Gold®. Additionally, we examined FIT pick-up, storage, return times and specimen collection. Materials and Methods: In vitro experiments with buffer containing FIT devices, inoculated with Hb-spiked stool. For 7 days, 144 samples were stored in groups of 36 at 4 °C, 22 °C, 30 °C, and 50 °C. Additionally, 54 samples were stored in groups of 18 at 34 °C, 42 °C and 50 °C for 20 h. Paired t-tests and repeated measure ANOVA assessed [Hb] change. Sixty-five screening participants completed a FIT-handling questionnaire. Results: After 7 days, mean [Hb] was stable at 30 °C (0.8 µg Hb/g;95 %CI: −1.5 to 3.1;p = 0.50). For 50 °C, mean [Hb] decreased within 2 days (−21.3 µg Hb/g;95 %CI: −30.2 to −12.5;p &lt; 0.001) and after 20 h (−63.0 µg Hb/g;95 %CI: −88.7 to −37.3;p &lt; 0.001), respectively. All other temperature categories showed significant mean [Hb] increase. Same-day FIT return was reported by 80 %. Eighty-seven percent experienced specimen collection as easy and 33 % kept the FIT refrigerated after collection. Conclusions: The FOB Gold® is suitable for CRC screening in tropical climates. Although most respondents indicated same-day sample return, we recommend avoiding FIT storage above 30 °C for longer than7 days.</p