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Background: In January 2020, the outbreak of COVID-19 in Wuhan, Hubespread to Guangdong that became the province with the second largest number of COVID-19 pa

Over the last half-decade or so, there has been an explosion in the recognition of hominin genera and species. We now have the late Miocene genera Orrorin and Sahelanthropus, the mid Pliocene genus Kenyanthropus, three new Pliocene species of Australopithecus (A. anamensis, A. garhi and A. bahrelghazali) and a sub species of Ardipithecus (Ar. r. kadabba) to contend with. Excepting also the more traditional species allocated to Paranthropus, Australopithecus and early Homo we are approaching around 15 species over 5 million years (excluding hominin evolution over the last one million years). Can such a large number of hominin species be justified? An examination of extant hominid (Gorilla gorilla, Pan troglodytes, and Pan paniscus) anatomical variability indicates that the range of fossil hominin variability supports the recognition of this large number of fossil species. It is also shown that not all hominins are directly related to the emergence of early Homo and as such have become extinct. Indeed the traditional australopithecine species 'A'. anamensis, 'A'. afarensis and 'A'. garhi are considered here to belong to a distinct genus Praeanthropus. They are also argued not be hominins, but rather an as yet undefined hominid group from which the more derived hominins evolved. The first hominin is represented by A. africanus or a hominin very much like it. The Paranthropus clade is defined by a derived heterochronic condition of peramorphosis, associated with sequential progenesis (contraction of successive growth stages) in brain and dental development, but a mixture of peramorphic and paedomorphic features in its craniofacial anatomy. Conversely, Kenyanthropus and Homo both share a pattern of peramorphosis, associated with sequential hypermorphosis (prolongation of successive growth stages) in brain development, and paedomorphosis processes in cranial, facial and dental development. This suggests, that these two clades share an important synapomorphy not recognised in the parsimony analyses, suggesting that they may form a sister group relationship to the exclusion of Paranthropus. This highlights the need to re-interpret phylogenetic results in terms of function and development. The rapid speciation and extinction as argued here is in keeping with other fossil groups in Africa at the Plio/Pleistocene transition. This emphasises that we must approach the pre-australopithecines and hominins as part of the endemic African fauna, and not in isolation to the evolutionary and climatic processes that were operating all around them.

Dear Editor, A genomic analysis of ≥75,000 cases and controls observed “considerable overlap between susceptibility loci for IBD and mycobacterial infection.”1 An editorial in the New England Journal of Medicine stated “common genetic signatures support, albeit indirectly, the proposal that a proportion of Crohn's disease cases may have a mycobacte-rial cause.”2 These observations lend considerable support to the increasing concern that IBD may be caused by a genetic susceptibility coupled with an associated mycobac-terial infection. We pose three critical questions.

Fatigue properties are an integral part of materials comparison activities and offer information for structural life estimation in many engineering applications. This article presents three general approaches to fatigue design, with a discussion on their respective attributes. These include infinite-life criterion, finite-life criterion, and damage tolerant criterion. The article describes the individual property requirements of these approaches. It also presents selected examples of properties that reflect some detail of these approaches.

The incomplete distribution of HIV therapy, coupled with uneven HIV transmission rates throughout a population, seem to predict a failure of commodity health care to reduce HIV incidence. Paradoxically, heterogeneity in HIV transmission risk combined with the appropriately targeted antiretroviral therapeutic strategy may offer a substantial public health benefit if HIV surveillance and treatment can be coordinated.

The design of a servohydraulic-controlled load frame for ‘real-time’ scanning electron microscope observations of cyclically loaded specimens is discussed. Details of a machine having a 1.3 kN capacity frame, control electronics and a video recording system are given. The equipment has been used to study fatigue in a copper single crystal, RR 58 aluminum alloy and IMI 829. The ability of the present equipment to reveal the surface response of materials subjected to cyclic loads has potential for the formulation of more rational material behaviour models.

Chromatographic and spectroscopic examination of extracts of members of Homoptera showed that the suborder can be divided into arylglycoside-containing (Aphidoidea-Coccoidea) and pterin-containing insects (the remainder of Homoptera). Leucopterin was isolated from two Homoptera. At least three classes of green pigment were found in the suborder. Earlier reports of simple pterins in aphids appear to relate to fluorescent glycosides. Aphids are rich in carotenoids in contrast to other members of the group.

The mass spectra of fifteen benzoquinones, variously substituted with methyl, hydroxyl, and methoxyl groups, are reported and discussed. The fragmentation patterns, which have been investigated in a number of cases by exact mass measurements and deuterium labelling, can be usefully correlated with the type of substituent and the nature of the substitution pattern.

Photoisomerisation of diaminated derivatives of 2,5-dimethyl-1,4-benzoquinone (p-xyloquinone) gives rise to benzoxazolines. The scope of this reaction, which affords new neterocyclic ring systems, is investigated.