Development of soil and vegetation climaxes in the Mount Kosciusko area,Australia

Summary Rates of development of alpine herbfield vegetation and alpine humus soils are studied in an area of fjaeldmark, on solifluction terraces, in the Mt. Kosciusko area of Australia.In relatively favourable sites, at the base of the solifluction terraces, the development from fjaeldmark to mature herbfield vegetation and soils can occur rapidly, within 40–50 years.Evidence is presented that much of the existing vegetation and soils at Kosciusko has developed from fjaeldmark by the successional processes described in this paper.

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Zusammenfassung Die Entwicklungsschnellheit der Vegetation einer Alpenwiese und eines alpinen Humus-Bodens wurden in einem Fjaeldmark-Gebiet, auf Solifluktions-Terrassen, in der Umgebung des Mt. Kosciusko, Australien, studiert. An verhaltnismäßig günstigen Stellen, am Fuße der Erdfluß-Terrassen, kann die Entwicklung von Fjaeldmark zur reifen Wiesenvegetation schnell vorsichgehen, innerhalb von 40–50 Jahren.Es wird angezeigt daß große Teile bestehender Vegetation und Boden beim Kosciusko durch den hier Beschriebenen Sukzessionsprozess aus Fjaeldmark entstanden sind.

     

Isolation in high frequency of rough variants of Mycobacterium intracellulare lacking C-mycoside glycopeptidolipid antigens.

Rough variants of serovars from the Mycobacterium avium-Mycobacterium intracellulare-Mycobacterium scrofulaceum complex were isolated in high frequency from pellicle growth of the wild-type strains. Rough morphology could be correlated with the lack of an outer cell wall sheath and its constituent C-mycoside glycopeptidolipids of both the serologically active and inactive types.     

Simple and Versatile 3D Printed Microfluidics Using Fused Filament Fabrication

The uptake of microfluidics by the wider scientific community has been limited by the fabrication barrier created by the skills and equipment required for the production of traditional microfluidic devices. Here we present simple 3D printed microfluidic devices using an inexpensive and readily accessible printer with commercially available printer materials. We demonstrate that previously reported limitations of transparency and fidelity have been overcome, whilst devices capable of operating at pressures in excess of 2000 kPa illustrate that leakage issues have also been resolved. The utility of the 3D printed microfluidic devices is illustrated by encapsulating dental pulp stem cells within alginate droplets; cell viability assays show the vast majority of cells remain live, and device transparency is sufficient for single cell imaging. The accessibility of these devices is further enhanced through fabrication of integrated ports and by the introduction of a Lego^®-like modular system facilitating rapid prototyping whilst offering the potential for novices to build microfluidic systems from a database of microfluidic components.     

Chick oviduct progesterone receptor binding of 15 beta, 17-dihydroxyprogesterone and its analogues

The structure of 16 alpha,17-epoxy-4-pregnene-3,20-dione was determined. The 20-carbonyl group eclipses the C(13)-C(17) bond. No direct correlation between the observed structure and its progestational activity could be inferred from our investigation.     

Three-dimensional cancer cell culture in high-yield multiscale scaffolds by shear spinning

Polymeric scaffolds comprising two size scales of microfibers and submicron fibers can better support three-dimensional (3D) cell growth in tissue engineering, making them an important class of healthcare material. However, a major manufacturing barrier hampers their translation into wider practical use: scalability. Traditional production of two-scale scaffolds by electrospinning is slow and costly. For day-to-day cell cultures, the scaffolds need to be affordable, made in high yield to drive down cost. Combining expertise from academia and industry from the United Kingdom and United States, this study uses a new series of high-yield, low-cost scaffolds made by shear spinning for tissue engineering. The scaffolds comprise interwoven submicron fibers and microfibers throughout as observed under scanning electron microscopy and demonstrate good capability to support cell culturing for tumor modeling. Three model human cancer cell lines (HEK293, A549 and MCF-7) with stable expression of GFP were cultured in the scaffolds and found to exhibit efficient cell attachment and sustained 3D growth and proliferation for 30 days. Cryosection and multiphoton fluorescence microscopy confirmed the formation of compact 3D cell clusters throughout the scaffolds. In addition, comparative growth curves of 2D and 3D cultures show significant cell-type-dependent differences. This work applies high-yield shear-spun scaffolds in mammalian tissue engineering and brings practical, affordable applications of multiscale scaffolds closer to reality. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2750, 2019.