Developmental mRNA clearance by PIWI-bound endo-siRNAs in Paramecium

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Oxygen toxicity causes cyclic damage by destabilizing specific Fe-S cluster-containing protein complexes

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Carbonyl ligand substitution at rhodium in the heterometallic cluster [PPN]2[Re7C(CO)21Rh(CO)2]. A reactivity comparison with mononuclear (n-C5H5Rh(CO)2 and related compounds

The heteometallic cluster compound [PPN]₂[Re₇C(CO)₂₁Rh(CO)₂] reacts with tertiary phosphines and phosphites selectively at the rhodium center to form the mono-substituted products [PPN]₂[Re₇C(CO) (L)]. Isolated compounds have been characterized by standard analytical and spectroscopic methods. Kinetics studies have shown that the reaction proceeds by an overall second-order process, first order in complex and first order in nucleophile. The second-order rate constants have been analysed in terms of electronic and steric effects. The substitution rates at the rhodium center in the cluster are compared with those for the analogous mononuclear complexes (n⁵-C₅H₄X)Rh(CO)₂ previously studied by Basolo and co-workers.     

Sensitivity to juvenile hormone is not reduced in clustering monarch butterflies, Danaus plexippus, in Australia

ABSTRACT. Female monarch butterflies, Danaus plexippus (L.) were collected from clusters in the Sydney region at weekly intervals after cluster formation. They were neck-ligated and injected with juvenile hormone (JH) in order to test for any period of lowered JH sensitivity during the non-reproductive clustering phase. Response was assessed by production of mature oocytes. In all weekly samples, the mean response was equal to or greater than that of newly emerged females reared and maintained in optimal conditions, and was substantially higher than that reported for diapausing monarchs in North American clusters. The result is further evidence for the absence of a true reproductive diapause in New South Wales populations.     

Application of Neural Networks Using the Volume Learning Algorithm for Quantitative Study of the Three-Dimensional Structure–Activity Relationships of Chemical Compounds

A volume learning algorithm for artificial neural networks was developed to quantitatively describe three-dimensional structure–activity relationships using as an example N-benzylpiperidine derivatives. The new algorithm combines two types of neural networks, the Kohonen and the feed-forward artificial neural networks, which are used to analyze the input grid data generated by the comparative molecular field approach. Selection of the most informative parameters using the algorithm helped reveal the most important spatial properties of the molecules, which affect their biological activities. Cluster regions determined using the new algorithm adequately predicted the activity of molecules from a control data set.     

Terminal mycelial clusters of tree roots; Their nutritional importance

Summary This study was concerned with properties of mycelia-agglutinated terminal root clusters, or mycoplasts,' of naturally reproduced seedlings ofPinus resinosa andPinus strobus. These rhizospheric root appendages, formed at the expense of the host plant's carbohydrates, exhibited high catalytic potential, cation exchange capacity, and content of exchangeable bases, including complexible cations. These attributes suggest that mycelial clusters are important components of tree-fungus symbiotic mechanism that increase availability of nutrients to the trees. The mycelial clusters apparently perform the function of mycorrhizal short roots which are often nonexistent under the conditions of reduced radiation in well-stocked forest stands.Research supported by the College of Agriculture and Life Sciences, University of Wisconsin, Madison, and the Wisconsin Department of Natural Resources.     

Overlapping Clusters of Tuberculosis Contacts: An Improved Sampling Strategy

A two stage without replacement strategy is proposed for estimating the population mean of overlapping clusters of contacts of tuberculosis cases. This sampling strategy is an improvement over the two sampling strategies proposed by SINGH (1988). A numerical illustration is provided by taking two populations of tuberculosis contacts from New York City; the percentage gain in efficiency varies from 3.70 to 24.99. The proposed improved sampling strategy may be useful to other contagious diseases in the different fields of biomedical sciences or similar situations in other fields.     

Rhodopirellula aestuarii sp. nov., a novel member of the genus Rhodopirellula isolated from brackish sediments collected in the Tagus River estuary,Portugal

Bacteria within the phylum Planctomycetota are biologically relevant due to unique characteristics among prokaryotes. Members of the genus Rhodopirellula can be abundant in marine habitats, however, only six species are currently validly described. In this study, we expand the explored genus diversity by formally describing a novel species. The pink-coloured strain ICT_H3.1^T was isolated from brackish sediments collected in the Tagus estuary (Portugal) and a 16S rRNA gene sequence-based analysis placed this strain into the genus Rhodopirellula (family Pirellulaceae). The closest type strain is Rhodopirellula rubra LF2^T, suggested by a similarity of 98.4% of the 16S rRNA gene sequence. Strain ICT_H3.1^T is heterotrophic, aerobic and able to grow under microaerobic conditions. The strain grows between 15 and 37 °C, over a range of pH 6.5 to 11.0 and from 1 to 8% (w/v) NaCl. Several nitrogen and carbon sources were utilized by the novel isolate. Cells have an elongated pear-shape with 2.0 ± 0.3 × 0.9 ± 0.2 µm in size. Cells of strain ICT_H3.1^T cluster in rosettes through a holdfast structure and divide by budding. Younger cells are motile. Ultrathin cell sections show cytoplasmic membrane invaginations and polar fimbriae. The genome size is 9,072,081 base pairs with a DNA G + C content of 56.1 mol%. Genomic, physiological and morphological comparison of strain ICT_H3.1^T with its relatives suggest that it belongs to a novel species within the genus Rhodopirellula. Hence, we propose the name Rhodopirellula aestuarii sp. nov., represented by ICT_H3.1^T (=CECT30431^T = LMG32464^T) as the type strain of this novel species.16S rRNA gene accession number: GenBank = OK001858.Genome accession number: The Whole Genome Shotgun project has been deposited at DDBJ/ENA/GenBank under the accession JAMQBK000000000. The version described in this paper is version JAMQBK010000000.     

In trans neuregulin3-Caspr3 interaction controls DA axonal bassoon cluster development

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