Fertile Prototaxites taiti: a basal ascomycete with inoperculate, polysporous asci lacking croziers

The affinities of Prototaxites have been debated ever since its fossils, some attaining tree-trunk proportions, were discovered in Canadian Lower Devonian rocks in 1859. Putative assignations include conifers, red and brown algae, liverworts and fungi (some lichenised). Detailed anatomical investigation led to the reconstruction of the type species, P. logani, as a giant sporophore (basidioma) of an agaricomycete (= holobasidiomycete), but evidence for its reproduction remained elusive. Tissues associated with P. taiti in the Rhynie chert plus charcoalified fragments from southern Britain are investigated here to describe the reproductive characters and hence affinities of Prototaxites. Thin sections and peels (Pragian Rhynie chert, Aberdeenshire) were examined using light and confocal microscopy; Přídolí and Lochkovian charcoalified samples (Welsh Borderland) were liberated from the rock and examined with scanning electron microscopy. Prototaxites taiti possessed a superficial hymenium comprising an epihymenial layer, delicate septate paraphyses, inoperculate polysporic asci lacking croziers and a subhymenial layer composed predominantly of thin-walled hyphae and occasional larger hyphae. Prototaxites taiti combines features of extant Taphrinomycotina (Neolectomycetes lacking croziers) and Pezizomycotina (epihymenial layer secreted by paraphyses) but is not an ancestor of the latter. Brief consideration is given to its nutrition and potential position in the phylogeny of the Ascomycota

Triceps ruptures

Triceps tendon tear is a relatively rare injury. Rupture is often associated with pre-existing systemic conditions or drug treatments, including the local or systemic of steroids. Patients tend to be men who practice sports and are from 30 to 50 years of age. Injury is commonly caused by falls on an outstretched hand, direct trauma on the elbow, or lifting against resistance. The clinical examination may detect pain, a palpable tendon gap, and extension weakness, while a pathognomonic flake sign may be seen on radiographs. Magnetic resonance imaging is widely accepted as the gold standard to evaluate the size and extension of the tear: triceps lesions often occur at the tendon insertion and result in either partial or total tears. Conservative treatment may be adopted for partial tears, with patients normally being able to return to sports or heavy activities after 4–6 months, when symptoms have resolved and strength has almost returned to normal. Nevertheless, patients need to be followed closely throughout this period to ensure that the lesion does not worsen. Primary repair of complete triceps injury should be performed as soon as possible to guarantee the recovery of daily functions and sports activity 3 and 5 months postoperatively, respectively, minimizing the risk of re-rupture at the same time. Postoperative care is based on elbow immobilization for 3–4 weeks and flexion block bracing for a further 2–3 weeks. Full flexion and active extension are normally initiated 6–8 weeks postoperatively. The recovery of extension strength against resistance starts after 12 weeks, whereas unrestricted activity is allowed after 5–6 months. Delayed diagnosis and treatment may complicate primary repair and lead to the need for reconstructive procedures. Small defect reconstruction by means of the anconeus rotation procedure ensures full ROM and strength in the long term. By contrast, an allograft using an Achilles tendon or hamstring autograft is required in chronic cases associated with large tendon gaps. A long rehabilitation period is to be expected in such cases, and muscle strength may only partially be regained. The postoperative protocol adopted in augmentation procedures is the same as that adopted for primary repair, though each step needs to be delayed by 2–3 weeks

Palaeozoic Innovations in the Micro- and Megafossil Plant Record: from the Earliest Plant spores to the Earliest Seeds

peer reviewe