SpMyb functions as an intramodular repressor to regulate spatial expression of CyIIIa in sea urchin embryos

The CyIIIa actin gene of Strongylocentrotus purpuratus is transcribed exclusively in the embryonic aboral ectoderm, under the control of 2.3 kb cis-regulatory domain that contains a proximal module that controls expression in early embryogenesis, and a middle module that controls expression in later embryogenesis. Previous studies demonstrated that the SpRunt-1 target site within the middle module is required for the sharp increase in CyIIIa transcription which accompanies differentiation of the aboral ectoderm, and that a negative regulatory region near the SpRunt-1 target site is required to prevent ectopic transcription in the oral ectoderm and skeletogenic mesenchyme. This negative regulatory region contains a consensus binding site for the myb family of transcription factors. In vitro DNA-binding experiments reveal that a protein in blastula-stage nuclei interacts specifically with the myb target site. Gene transfer experiments utilizing CyIIIa reporter constructs containing oligonucleotide substitutions indicate that this site is both necessary and sufficient to prevent ectopic expression of CyIIIa. Synthetic oligonucleotides containing the myb target site were used to purify a protein from sea urchin embryo nuclear extracts by affinity chromatography. This protein is immunoprecipitated by antibodies specific to the evolutionarily conserved myb domain, and amino acid sequences obtained from the purified protein were found to be identical to sequences within the myb domain. Sequence information was used to obtain cDNA clones of SpMyb, the S. purpuratus member of the myb family of transcription factors. Through interactions within the middle module, SpMyb functions to repress activation of CyIIIa in the oral ectoderm and skeletogenic mesenchyme

Hydrogeology and drilling phase 1 for Scott Creek catchment

Scott Creek Catchment is the first of a number of catchments that will be used as case studies to investigate the sustainability of groundwater resources in the Mount Lofty Ranges over the next 45 years. This report provides a collation of background information for the Scott Creek Catchment including geological, hydrological, meteorological and surface water quality data. Site selection criteria, drilling methods, construction details and lithological logs are presented for the first phase of drilling in this catchment. A total of nine wells (one completed in the Quaternary alluvium and eight in the fractured Woolshed Flat Shale) were drilled at strategic locations on either side of Scott Creek upstream of the weir at Scott Bottom. These wells will be used for a variety of hydraulic and hydrochemical tests to define the local hydrogeology in terms of streamaquifer interactions and groundwater recharge and flow rates.repor

Light and Life: Exotic Photosynthesis in Binary Star Systems

The potential for hosting photosynthetic life on Earth-like planets within binary/multiple stellar systems was evaluated by modelling the levels of photosynthetically active radiation (PAR) such planets receive. Combinations of M and G stars in: (i) close-binary systems; (ii) wide-binary systems and (iii) three-star systems were investigated and a range of stable radiation environments found to be possible. These environmental conditions allow for the possibility of familiar, but also more exotic forms of photosynthetic life, such as infrared photosynthesisers and organisms specialised for specific spectral niches.Comment: Accepted for publication in: Astrobiolog

Cellular Models of Aggregation-Dependent Template-Directed Proteolysis to Characterize Tau Aggregation Inhibitors for Treatment of Alzheimer's Disease

Copyright © 2015, The American Society for Biochemistry and Molecular Biology. Acknowledgements-We thank Drs Timo Rager and Rolf Hilfiker (Solvias, Switzerland) for polymorph analyses.Peer reviewedPublisher PD

Guidance of ultraviolet light down to 190 nm in a hollow-core optical fibre

We report an anti-resonant hollow core fibre with ultraviolet transmission down to 190 nm, covering the entire UV-A, UV-B and much of the UV-C band. Guidance from 190 - 400 nm is achieved apart for a narrow high loss resonance band at 245 - 265 nm. The minimum attenuation is 0.13 dB/m at 235 nm and 0.16 dB/m at 325 nm. With an inscribed core diameter of ~ 12 $\mu$m, the fibre's bend loss at 325 nm was 0.22 dB per turn for a bend radius of 3 cm at 325 nm

Seasonal activity levels of a farm-island population of striated caracaras (Phalcoboenus australis) in the Falkland Islands

Harrington KJ, Fahlbusch JA, Langrock R, Therrien J-F, Houtz JL, McDonald BI. Seasonal activity levels of a farm-island population of striated caracaras (Phalcoboenus australis) in the Falkland Islands. Animal Biotelemetry. 2020;8(1): 27

Magnetic Monopoles in String Theory

Magnetic monopole solutions to heterotic string theory are discussed in toroidal compactifications to four spacetime dimensions. Particular emphasis is placed on the relation to previously studied fivebrane solutions in ten dimensions and on the possibility of constructing exact monopole solutions related to symmetric fivebranes.Comment: 24 pages (Corrected title