Filamentous cyanobacteria preserved in masses of fungal hyphae from the Triassic of Antarctica

This work is licensed under a Creative Commons Attribution 4.0 International License.Permineralized peat from the central Transantarctic Mountains of Antarctica has provided a wealth of information on plant and fungal diversity in Middle Triassic high-latitude forest paleoecosystems; however, there are no reports as yet of algae or cyanobacteria. The first record of a fossil filamentous cyanobacterium in this peat consists of wide, uniseriate trichomes composed of discoid cells up to 25 µm wide, and enveloped in a distinct sheath. Filament morphology, structurally preserved by permineralization and mineral replacement, corresponds to the fossil genus Palaeo-lyngbya, a predominantly Precambrian equivalent of the extant Lyngbya sensu lato (Oscillatoriaceae, Oscillatoriales). Specimens occur exclusively in masses of interwoven hyphae produced by the fungus Endochaetophora antarctica, suggesting that a special micro-environmental setting was required to preserve the filaments. Whether some form of symbiotic relationship existed between the fungus and cyanobacterium remains unknown

RELATIONSHIPS BETWEEN ROTATOR CUFF STRENGTH PARAMETERS AND THROWING VELOCITY OF COLLEGE BASEBALL PLAYERS

Pitching a baseball is a complex, highly skilled movement that has been divided into four stages by sports researchers. In examining the throwing motion, researchers have: 1) attempted to find the most significant muscle groups of the upper extremity that contribute to throwing velocity (Jobe, 1987; Pedegna, 1982 and Toyoshima and Hoshikawa, 1974); 2) concluded that the shoulder and internal and external rotator groups are the most significant contributors to the throwing motion (Alderink and Kuck, 1986; Cain, Mutschler, Fu and Lee, 1987, Cook, Gray, Savinar-Nogue, Medeiros, 1987, and Pappas, Zawacki and MacCarthy, 1985); and 3) demonstrated that the motions of shoulder rotation are important during tht throwing performance (Atwater, Feltner and Dapena, 1986; Gainor, 1980; and Tullos and King, 1973)

Macrofossil Evidence For Pleuromeialean Lycophytes From the Triassic of Antarctica

This is the publisher's version, which is also available electronically from: http://dx.doi.org/10.4202/app.2010.0022Triassic microfloras from Antarctica contain abundant lycophyte spores. However, macrofossils of this group of plants are missing, and thus the precise affinities of the spore producers remain unknown. Macrofossil remains of a pleuro− meialean lycophyte, including an incomplete strobilus, isolated sporophylls and sporangia, as well as abundant mega− spores, occur on a single rock sample from the central Transantarctic Mountains. Also occurring on the same surface is Mesenteriophyllum serratum, a strap−shaped leaf morphotype of uncertain affinity previously known only from the Kyrgyz Republic and the Taimyr Peninsula. The leaves display alternating transverse ridges and depressions that are sim− ilar to structures seen in compressed leaves of various isoetalean lycophytes. Leaf morphology and anatomy, together with the close association of the other lycophyte remains, suggest that M. serratum represents a pleuromeialean lycophyte leaf, which was part of the same plant that produced the sporophylls and sporangia. Sedimentological data indicate that this lycophyte inhabited a swampy, probably coal−forming overbank environment, which contrasts with the assumed xero− to halophytic habit of many other pleuromeialean lycophytes

Social Work, Politics, and Social Policy Education: Applying a Multidimensional Framework of Power

The call to promote social justice sets the social work profession in a political context. In an effort to enhance social workers’ preparedness to engage in political advocacy, this article calls on educators to integrate a broad theoretical understanding of power into social policy curricula. We suggest the use of a multidimensional conceptualization of power that emphasizes mechanisms of decision making, agenda control, and attitude formation. We then apply these mechanisms to demonstrate how two prominent features of contemporary politics—party polarization and racially biased attitudes—affect the ability of social workers to influence policy. Finally, we suggest content that social work educators can integrate to prepare future social workers to engage in strategic and effective social justice advocacy

Structurally preserved fungi from Antarctica: diversity and interactions in late Palaeozoic and Mesozoic polar forest ecosystems

Chert and silicified wood from the Permian through Cretaceous of Antarctica contain abundant information on fungal diversity and plant-fungal interactions. The chert deposits represent a particularly interesting setting for the study of plant-fungal interactions because they preserve remains of distinctive high latitude forest ecosystems with polar light regimes that underwent a profound climate change from icehouse to greenhouse conditions. Moreover, some of the cherts and wood show the predominance of extinct groups of seed plants (e.g. Glossopteridales, Corystospermales). Over the past 30 years, documentation of fossil fungi from Antarctica has shifted from a by-product of plant descriptive studies to a focused research effort. This paper critically reviews the published record of fungi and fungal associations and interactions in the late Palaeozoic and Mesozoic cherts and silicified wood from Antarctica;certain fungal palynomorphs and fungal remains associated with adpression fossils and cuticles are also considered. Evidence of mutualistic (mycorrhizal), parasitic and saprotrophic fungi associated with plant roots, stems, leaves and reproductive organs is presented, together with fungi occurring within the peat matrix and animal-fungus interactions. Special attention is paid to the morphology of the fungi, their systematic position and features that can be used to infer fungal nutritional modes

Protoascon missouriensis, a complex fossil microfungus revisited

The Carboniferous microfungus Protoascon missouriensis has been interpreted variously as an ascomycete, chytridiomycete, zygomycete and oomycete. We offer a more complete interpretation based on a re-examination of the type material that suggests the fossil represents an (a)zygosporangium-suspensor complex of a zygomycete comparable to some modern members of the Mucorales

Paleomycology of the Princeton Chert I. Fossil hyphomycetes associated with the early Eocene aquatic angiosperm, Eorhiza arnoldii

This is the publisher's version, also available electronically from http://www.mycologia.org/content/105/3/521The Eocene (~ 48.7 Ma, Ypresian–Lutetian) Princeton Chert of British Columbia, Canada, has long been recognized as a significant paleobotanical locality, and a diverse assemblage of anatomically preserved fossil plants has been extensively documented. Co-occurring fossil fungi also have been observed, but the full scope of their diversity has yet to be comprehensively assessed. Here, we present the first of a series of investigations of fossilized fungi associated with the silicified plants of the Princeton Chert. This report focuses on saprotrophic, facultative-aquatic hyphomycetes observed in cortical aerenchyma tissue of an enigmatic angiosperm, Eorhiza arnoldii. Our use of paleontological thin sections provides the opportunity to observe and infer developmental features, making it possible to more accurately attribute two hyphomycetes that were observed in previous studies. These comprise multiseptate, holothallic, chlamydospore-like phragmoconidia most similar to extant Xylomyces giganteus and basipetal phragmospore-like chains of amerospores like those of extant Thielaviopsis basicola. We also describe a third hyphomycete that previously has not been recognized from this locality; biseptate, chlamydosporic phragmoconidia are distinguished by darkly melanized, inflated apical cells and are morphologically similar to Brachysporiella rhizoidea or Culcitalna achraspora

Mixed convection in a rotating porous cavity having local heater

Numerical simulation of convective heat transfer inside a rotating porous square cavity with local heater of constant temperature has been performed. Governing equations formulated on the basis of mass, momentum and energy conservation laws written using the dimensionless stream function, vorticity and temperature have been solved by the finite difference method. The effects of Rayleigh and Taylor numbers on periodic flow and heat transfer have been studied