Tetranychid mites of Tasmania

Formerly only four species of the family Tetranychidae had been recorded from Tasmania. Collections of mites from both introduced and native plants have revealed that the family is represented by ten genera of which two are new. Fifteen species, five being new, are now recorded from the State. The following new genera and species are described:- New genera-Synonychus, Tylonychus. New species-Synonychus eucalypti, Eutetranychus acaciae, Tylonychus tasmaniensis, Eotetranychus hudsoni and Tetranychus rhagodiae. In addition the male of Schizonobia sycophanta Wom. is described for the first time

The Vulcan Works, Southport : the archaeology of an Edwardian car factory

The widespread adoption of the motor car had what was perhaps the greatest impact on the physical and social landscape of 20th-century Britain, and yet virtually none of the early car factories have been subject to formal archaeological investigation. In 2019-20, Salford Archaeology carried out a comprehensive survey of the former Vulcan Works, a purpose-built factory that was erected near Southport in 1907 by Thomas and Joseph Hampson, two pioneers of the British motor-manufacturing industry. Initially, this ‘state-of-the-art’ factory comprised an architecturally impressive two-storey office with a single-storey machine and erecting shop to the rear, together with the associated power plant. Extensive additions had increased the size of the works to more than 3.6 hectares by 1924, and whilst the buildings were repurposed as a general engineering works in 1937, the original Edwardian car factory remained largely unaltered. The archaeological survey, coupled with historical research and limited excavation, has provided a unique record of a rare survivor of Britain’s fledgling car-manufacturing industry prior to its demolition

Minimal standards for describing new species belonging to the families Campylobacteraceae and Helicobacteraceae : Campylobacter, Arcobacter, Helicobacter and Wolinella spp.

Ongoing changes in taxonomic methods, and in the rapid development of the taxonomic structure of species assigned to the Epsilonproteobacteria have lead the International Committee of Systematic Bacteriology Subcommittee on the Taxonomy of Campylobacter and Related Bacteria to discuss significant updates to previous minimal standards for describing new species of Campylobacteraceae and Helicobacteraceae. This paper is the result of these discussions and proposes minimum requirements for the description of new species belonging to the families Campylobacteraceae and Helicobacteraceae, thus including species in Campylobacter, Arcobacter, Helicobacter, and Wolinella. The core underlying principle remains the use of appropriate phenotypic and genotypic methods to characterise strains sufficiently so as to effectively and unambiguously determine their taxonomic position in these families, and provide adequate means by which the new taxon can be distinguished from extant species and subspecies. This polyphasic taxonomic approach demands the use of appropriate reference data for comparison to ensure the novelty of proposed new taxa, and the recommended study of at least five strains to enable species diversity to be assessed. Methodological approaches for phenotypic and genotypic (including whole-genome sequence comparisons) characterisation are recommended

Sperm death and dumping in Drosophila

Mating with more than one male is the norm for females of many species. In addition to generating competition between the ejaculates of different males, multiple mating may allow females to bias sperm use. In Drosophila melanogaster, the last male to inseminate a female sires approximately 80% of subsequent progeny. Both sperm displacement, where resident sperm are removed from storage by the incoming ejaculate of the copulating male, and sperm incapacitation, where incoming seminal fluids supposedly interfere with resident sperm, have been implicated in this pattern of sperm use. But the idea of incapacitation is problematic because there are no known mechanisms by which an individual could damage rival sperm and not their own. Females also influence the process of sperm use, but exactly how is unclear. Here we show that seminal fluids do not kill rival sperm and that any 'incapacitation' is probably due to sperm ageing during sperm storage. We also show that females release stored sperm from the reproductive tract (sperm dumping) after copulation with a second male and that this requires neither incoming sperm nor seminal fluids. Instead, males may cause stored sperm to be dumped or females may differentially eject sperm from the previous mating

First multi-locus sequence typing scheme for Arcobacter spp.

<p>Abstract</p> <p>Background</p> <p><it>Arcobacter </it>spp. are a common contaminant of food and water, and some species, primarily <it>A. butzleri </it>and <it>A. cryaerophilus</it>, have been isolated increasingly from human diarrheal stool samples. Here, we describe the first <it>Arcobacter </it>multilocus sequence typing (MLST) method for <it>A. butzleri</it>, <it>A. cryaerophilus</it>, <it>A. skirrowii, A. cibarius </it>and <it>A. thereius</it>.</p> <p>Results</p> <p>A sample set of 374 arcobacters, including 275 <it>A. butzleri</it>, 72 <it>A. cryaerophilus</it>, 15 <it>A. skirrowii </it>and 8 <it>A. cibarius </it>isolates from a wide variety of geographic locations and sources, was typed in this study. Additionally, this sample set contained four strains representing a new <it>Arcobacter </it>species, <it>A. thereius</it>. The seven loci used in the four-species <it>Arcobacter </it>MLST method are the same as those employed previously in <it>C. jejuni</it>, <it>C. coli</it>, <it>C. helveticus </it>and <it>C. fetus </it>(i.e. <it>aspA</it>, <it>atpA</it>(<it>uncA</it>), <it>glnA</it>, <it>gltA</it>, <it>glyA, pgm </it>and <it>tkt</it>). A large number of alleles were identified at each locus with the majority of isolates containing a unique sequence type. All <it>Arcobacter </it>isolates typed in this study contain two <it>glyA </it>genes, one linked to <it>lysS </it>(<it>glyA1</it>) and the other linked to <it>ada </it>(<it>glyA2</it>). <it>glyA1 </it>was incorporated into the <it>Arcobacter </it>MLST method while <it>glyA2 </it>was not because it did not increase substantially the level of discrimination.</p> <p>Conclusion</p> <p>No association of MLST alleles or sequence types with host or geographical source was observed with this sample set. Nevertheless, the large number of identified alleles and sequence types indicate that this MLST method will prove useful in both <it>Arcobacter </it>strain discrimination and in epidemiological studies of sporadic <it>Arcobacter</it>-related gastroenteritis. A new <it>Arcobacter </it>MLST database was created <url>http://pubmlst.org/arcobacter/</url>; allele and ST data generated in this study were deposited in this database and are available online.</p

Ownership-dependent mating tactics of minor males of the beetle Librodor japonicus (Nitidulidae) with intra-sexual dimorphism of mandibles

Intra-sexual dimorphism is found in the weapons of many male beetles. Different behavioral tactics to access females between major and minor males, which adopt fighting and alternative tactics, respectively, are thought to maintain the male dimorphism. In these species major males have enlarged weapons that they use in fights with rival males. Minor males also have small weapons in some of these species, and it is unclear why these males possess weapons. We examined the hypothesis that minor males might adopt a fighting tactic when their status was relatively high in comparison with that of other males (e.g., ownership of a territory). We observed the behavioral tactics of major and minor males of the beetle Librodor japonicus, whose males have a dimorphism of their mandibles. Major males fought for resources, whereas minor males adopted two status-dependent tactics, fighting and sneaking, to access females, depending on their ownership of a sap site. We suggest that ownership status-dependent mating tactics in minor males may maintain the intra-sexual dimorphism in this beetle.</p

A rapidly spinning supermassive black hole at the centre of NGC 1365

Broad X-ray emission lines from neutral and partially ionized iron observed in active galaxies have been interpreted as fluorescence produced by the reflection of hard X-rays off the inner edge of an accretion disk. In this model, line broadening and distortion result from rapid rotation and relativistic effects near the black hole, the line shape being sensitive to its spin. Alternative models in which the distortions result from absorption by intervening structures provide an equally good description of the data, and there has been no general agreement on which is correct. Recent claims that the black hole (2 × 10^6 solar masses) at the centre of the galaxy NGC 1365 is rotating at close to its maximum possible speed rest on the assumption of relativistic reflection. Here we report X-ray observations of NGC 1365 that reveal the relativistic disk features through broadened Fe-line emission and an associated Compton scattering excess of 10–30 kiloelectronvolts. Using temporal and spectral analyses, we disentangle continuum changes due to time-variable absorption from reflection, which we find arises from a region within 2.5 gravitational radii of the rapidly spinning black hole. Absorption-dominated models that do not include relativistic disk reflection can be ruled out both statistically and on physical grounds

Accreting Black Holes

This chapter provides a general overview of the theory and observations of black holes in the Universe and on their interpretation. We briefly review the black hole classes, accretion disk models, spectral state classification, the AGN classification, and the leading techniques for measuring black hole spins. We also introduce quasi-periodic oscillations, the shadow of black holes, and the observations and the theoretical models of jets.Comment: 41 pages, 18 figures. To appear in "Tutorial Guide to X-ray and Gamma-ray Astronomy: Data Reduction and Analysis" (Ed. C. Bambi, Springer Singapore, 2020). v3: fixed some typos and updated some parts. arXiv admin note: substantial text overlap with arXiv:1711.1025